Source Code of Ratopak/Pegasus Spyware Targeting the Financial Sector Recently Leaked

On July 6, 2018, a post claiming to contain the source code of Carbanak group malware was published on a Russian-speaking underground forum. Soon after the sharing of the code on the Russian underground, it was uploaded by an unknown actor to the text-sharing platform Pastebin, making it accessible to all. At the same time, malware researchers analyzing the shared code discovered the malware is not one used by the Carbanak group, but rather, it is the Ratopak/Pegasus spyware, used in attacks against Russian banks in 2016. Continue reading “Source Code of Ratopak/Pegasus Spyware Targeting the Financial Sector Recently Leaked”

Cybercriminals Integrate Exploit for CVE-2018-8174 into Numerous Attack Tools

The CVE-2018-8174 vulnerability, also dubbed “Double Kill,” was discovered in the beginning of May 2018, when it was exploited as a 0-day in an APT attack leveraging malicious Office files in China. The vulnerability affects users with Internet Explorer installed, either after they browse the web or after they open crafted Office documents – even if the default browser on the victim’s machine is not set to IE. Moreover, it will also affect IE11, even though VBScript is no longer supported by using the compatibility tag for IE10. Microsoft patched the vulnerability on May 8, 2018. Continue reading “Cybercriminals Integrate Exploit for CVE-2018-8174 into Numerous Attack Tools”

Sharp Rise in Mining-Related Malware on the Russian-speaking Underground

Verint’s powerful portfolio of interception and monitoring solutions provides full monitoring and operational value. Dedicated systems address separate real-time and retroactive investigation needs, for lawful monitoring, field operations and background research. In the case below, we have used our Cyber and Webint suite to constantly monitor, collect and analyze malware-related items, to gain actionable intelligence and perform the investigation. Continue reading “Sharp Rise in Mining-Related Malware on the Russian-speaking Underground”

Shadow Brokers’ Massive Leak Spreads Quickly Across the Dark Web

Since April 14th, when the Shadow Brokers leaked a new batch of files allegedly affiliated with Equation Group – an APT threat actor suspected of being tied to the NSA – Darknet forum members have been sharing the leaked attack tools and zero-day exploits among themselves. Continue reading “Shadow Brokers’ Massive Leak Spreads Quickly Across the Dark Web”

Exploit Kits Out, Loaders and Macros Back in

During 2016, we witnessed the collapse of three major exploit kits that were previously used for massive malware delivery: Nuclear (first), Angler and then Neutrino (later). Along with other more private EKs (such as Magnitude), they caused major damage in previous years and served as infection vectors for many malicious malware-distributing campaigns. Continue reading “Exploit Kits Out, Loaders and Macros Back in”

The Shade (Troldesh) Ransomware: One More Soldier in the Army of Encryption Miscreants

Written by Mickael S. and Tanya K.

Last week, SenseCy analysts happened upon a new sample of Shade ransomware, also known as Troldesh, which uses a no_more_ransom extension for encrypted files. This ransomware is far from famous, lacking the glorious Continue reading “The Shade (Troldesh) Ransomware: One More Soldier in the Army of Encryption Miscreants”

Insider Threats – Sometimes it is your Colleagues, and not Remote Attackers

Insiders pose the most substantial threat to organizations everywhere, a recent across-the-board study conducted by IBM demonstrates. Although in the majority of the cases, the insider is an employee of the company, he could also be a third party, such as an external contractor, a consultant or a business partner. An insider generally has all the Continue reading “Insider Threats – Sometimes it is your Colleagues, and not Remote Attackers”

Cerber Ransomware JavaScript Loader Goes Undetected

We have been closely monitoring Cerber ransomware since it first emerged on a Russian password-protected forum, offered as-a-service for members only.

At present, Cerber ransomware constitutes a sophisticated malware threat to organizations. (it was responsible for more than 25% of the total number of ransomware infections recorded worldwide in June 2016, according to Microsoft). Files encrypted by Cerber are currently non-decryptable.

On August 23, 2016, a member of the same closed forum where Cerber ransomware is traded posted a detailed analysis of the loader that the malware uses to install itself. According to his post, he did this after hearing that the loader is very useful and capable of installing any malware without detection. His conclusion was that the loader does not employ any extraordinary methods to install the ransomware, but its tremendous advantage of being fully undetectable by AV programs is due to the usage of several rare code functions that are difficult to emulate.

First, he posted the full obfuscated code of the loader, explaining parts of it:

  • Replacement of the Eval function, i.e. it receives a parameter that contains JavaScript code and executes it. Usually, AV programs emulate this function. Replacing the Eval function blocks this emulation.
  • Another part of the code creates a Desktop shortcut, probably also as an anti-emulator measure (the post writer comments that in his opinion AV would quickly detect it).
  • The next part of the code is obfuscated – a HEX code which is divided and deobfuscated using XOR.After deobfuscation, we can see that the code contains anti-emulation.
  • Then a random string is created and a path from %TEMP% environment obtained for it.
  • The next stage involves downloading the malicious file from an URL address and saving it in the system.
  • A parameter is added to the header to block AV bots and researchers: setRequestHeader(‘cerber’,’true’)
  • If the malicious payload was downloaded properly, it is executed.
  • Finally, the Eval alternative is launched.

Summarizing the analysis, the post author concludes that the advantages of the loader are a good implementation of the payload download and execution and errors control. The disadvantages he mentions are weak implementation of obfuscation and anti-emulation, and low level of usability functionality. He also attached an AV scanner report from August 23, showing a detection rate of 15/40.

Several days later, on August 27, 2016, the same forum member posted that he had analyzed the latest version of the loader and was surprised by the fact it is totally undetectable by AV programs. Moreover, this version is capable of installing payloads from several alternative URL addresses and it uses improved debugging. This version does not use anti-emulation at all, but employs a unique method that totally blocks the AV syntax emulation. 

Below is a description of the main techniques used by the loader to remain undetected:

  • Replacement of the Eval function (even though it is a simple technique, it is used extensively by JS packers and therefore cannot be detected by AV as malicious).
  • The part of the code that avoids emulation is an array that contains random data, with the first element being the important one. The functions Math.floor and Math.random always output only the first element in the array and AV cannot properly emulate them. Full undetectability is achieved by using these two functions.

The emulator will always output one single value and will never reach the part of the array when the right value is located. As a result, the emulator cannot perform the calculations, a critical error occurs and the AV programs are unable to identify the loader as a malicious file.

1
The message that analyzes what code feature allows the malware to avoid AV detection

The post author attached an AV scanner report showing a 0/35 detection rate (as of August 27, 2016).

2
The scan showing that the loader is not detected by AV engines

Russian Cyber Criminal Underground – 2015: The Prosperity of Ransomware and Office Exploits

The prominent products traded during 2015 on Russian underground forums were Ransomware programs and exploits targeting Microsoft Office. Prices on the Russian Underground have remained unchanged during the past two years, due to the vigorous competition between sellers on these platforms. Different kinds of services, such as digital signing for malicious files, injections development for MitM attacks and Crypting malware to avoid detection were also extremely popular on Russian forums.

Check out the new Infographic from SenseCy illustrating key trends observed on Russian underground in 2015.

Please contact us to receive your complimentary 2015 SenseCy Annual Cyber Threat Intelligence Report: https://www.sensecy.com/contact

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