PyLocky Ransomware Source Code Leaked Online

PyLocky represents a new ransomware strain that was detected in the wild in late July 2018, and whose volume of infections increased throughout the month of August. The malware is usually distributed through malspam emails claiming to link to a fake payment invoice, and it features advanced anti-detection and anti-sandbox capabilities. Notably, infection telemetry data shows that PyLocky mainly targeted France and German cyberspace, but ransom notes also exist in Italian and Korean.

On September 11, 2018, we detected the leakage of PyLocky source code on Pastebin. Thus far, the incident has not received media attention. However, the paste was viewed by over 2,500 users. Therefore, our assessment is that this leakage might lower the barrier to entry for wannabe cybercriminals, possibly leading to an increase in malspam campaigns distributing this malware strain in the future. Continue reading “PyLocky Ransomware Source Code Leaked Online”

Massive Cyber Attack Causing Chaos as World Still Recovers from WannaCry

In the past few hours, multiple reports were published about a mass-scale cyber-attack taking place in Ukraine. The attack hit multiple government resources, as well as corporate, financial and critical infrastructure systems (Kyiv subway and airport, electricity and oil companies, etc). Continue reading “Massive Cyber Attack Causing Chaos as World Still Recovers from WannaCry”

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”

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.

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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).

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

New Infographic – Tips on Avoiding Ransomware Attacks

Ransomware is emerging as a predominant online security threat to both home users and businesses, with numerous reports appearing every day on ransomware attacks against organizations across the globe. SenseCy analysts have prepared a short list of security measures recommended for any business to help avoid these attacks. Check out the tips and stay safe!

Defending against Ransomware

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

Russian_underground_final

Handling a Ransomware Attack

A recent wave of ransomware attacks has hit countries around the world, with a large number of infections reported in the United States, the United Kingdom, Germany and Israel. It appears that the attackers have no specific target, since the attacks have struck hospitals, financial institutions and private institutions, indicating that no specific industry has been targeted.

In Israel, two types of ransomware were identified in the most recent attacks: the familiar TeslaCrypt and the new ransomware, Locky.

The Evolution of Ransomware

The vigorous usage of ransomware tools by cybercriminals and their success in this area has led to the development of new ransomware and the constant upgrading of known models. During the past several months, researchers have reported on the development of ransomware that is capable of file encryption without Internet connection, i.e., they do not communicate with their C&C servers for the encryption process.

New ransomware tools that were reported are Locky ransomware, whose modus operandi resembles the Dridex banking Trojan, and a new version of CTB-Locker that attacks web servers.

Additionally, RaaS (Ransom-as-a-Service) offers are becoming popular on closed DeepWeb and Darknet forums. These services allow potential attackers to easily create ransomware stubs, paying with profits from future successful infections. Recently, we identified a new RaaS dubbed Cerber ransomware, which is offered on a Russian underground forum. Previously it was ORX-Locker, offered as a service via a platform hosted on an .onion server.

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The ransom message presented by the Cerber ransomware

Ransomware Distribution

The majority of the distribution vectors of ransomware stubs involve some kind of social engineering trap, for example, email messages including malicious Office files, spam messages with nasty links or malvertising campaigns exploiting vulnerable WordPress or Joomla websites with an embedded malevolent code. The distribution also takes advantage of Macro commands and exploit kits, such as Nuclear or Angler. Sometimes browser vulnerabilities are exploited, as well as stolen digital certificates.

In November 2015, attempts to deliver ransomware to Israeli clients were identified. In this case, the attackers spoofed a corporate email address and tried to make recipients believe the email was sent from a company worker.

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RaaS offered on a Darknet forum

Handling a Ransomware Attack

Please find below our suggestions for recommended action to avoid ransomware attacks on an organization, and how to deal with an attack after infection:

Defend Your Organization from Potential Threats

  • Train your employees – since the human link is the weakest link in the organizational cybersecurity and the majority of the cases involve social engineering on one of the employees, periodical employee briefing is extremely important. Specify the rules regarding using the company systems, and describe what phishing messages look like.
  • Raise awareness regarding accepting files that arrive via email messages – instruct your employees not to open suspicious files or files sent from unfamiliar senders. Consider implementing an organizational policy addressing such files. We recommend blocking or isolating files with the following extensions: js (JavaScript), jar (Java), bat (Batch file), exe (executable file), cpl (Control Panel), scr (Screensaver), com (COM file) and pif (Program Information file).
  • Disable running of Macro scripts on Office files sent via email – in recent months, many cases of ransomware attacks employing this vector were reported. Usually, Macro commands are disabled by default and we do not recommend enabling them. In addition, we suggest using Office Viewer software to open Word and Excel files.
  • Limit user privileges and constantly monitor the workstations – careful management of user privileges and limited administrator’s privileges may help in avoiding the spread of the ransomware in the organizational network. Moreover, monitoring the activity on workstations will be useful for early detection of any infection and blocking it from propagating to other systems and network resources.
  • Create rules that block programs from executing from AppData/LocalAppData folders. Many variants of the analyzed ransomware are executed from these directories, including CryptoLocker. Therefore, the creation of such rules may reduce the encryption risk significantly.
  • Install a Russian keyboard – while monitoring closed Russian forums where several ransomware families originated, we discovered that many of them will check if the infected computer is located in a post-Soviet country. Usually, this check is performed by detecting which keyboard layout is installed on the machine. If a Russian (or other post-Soviet language) keyboard layout is detected, the ransomware will not initiate the encryption process.
  • Keep your systems updated – in many cases, hackers take advantage of outdated systems to infiltrate the network. Therefore, frequent updates of the organizational systems and implementing the published security patch will significantly reduce the chances of infection.
  • Use third-party dedicated software to deal with the threat – many programs aimed at addressing specific ransomware threats are constantly being released. One is Windows AppLocker, which is included in the OS and assists in dealing with malware. We recommend contacting the organizational security vendor and considering the offered solutions.
  • Implement technical indicator and YARA rules in the company organizations. We provide our clients with intelligence items accompanied by technical indicators. Additionally, a dedicated repository that includes ransomware indicators was launched.
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    A closed forum member looks to blackmail companies using ransomware

    What if I am Already Infected?

  • Restore your files – some ransomware tools create a copy of the file, encrypt it and then erase the original file. If the deletion is performed via the OS erase feature, there is a chance to restore the files, since in majority of the cases, the OS does not immediately overwrite the deleted filed.
  • Decryption of the encrypted files – the decryption will be possible if you were infected by one of these three ransomware types: Bitcryptor, CoinVault or Linux.Encoder.1. Therefore, detecting the exact kind of ransomware that attacked the PC is crucial.
  • Back-up files on a separate storage device regularly – the best practice to avoid damage from a ransomware attack is to backup all your important files on a storage disconnected from the organizational network, since some ransomware variants are capable of encrypting files stored on connected devices. For example, researchers recently reported a ransomware that encrypted files stored on the Cloud Sync folder.
  • If ransomware is detected in the organization, immediately disconnect the infected machine from the network. Do not try to remove the malware or to reboot the system before identifying the ransomware. In some cases, performing one of these actions will make the decryption impossible, even after paying the ransom.

SenseCy Investigates The English-Language Underground

In 2015 we saw an active underground trading of exploits, botnets and spam tools. The number of Ransomware sales were much lower than it was expected by cyber security experts. Investigate the key trends in hacking tools commerce observed on the English-language underground in 2015 from our short Infographic.

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

English-language underground_2015

SenseCy 2015 Annual Cyber Threat Intelligence Report

Written and prepared by SenseCy’s Cyber Intelligence analysts.

SenseCy’s 2015 Annual CTI Report spans the main trends and activities monitored by us in the different cyber arenas including the world of Arab hacktivism, the Russian underground, the English-speaking underground, the Darknet and the Iranian underground. In addition, we have listed the major cyber incidents that occurred in 2015, and the most prominent attacks against Israeli organizations.

The following is an excerpt from the report. To receive a copy, please send a request to: info@sensecy.com

Executive Summary

2015 was a prolific year for cyber threats, so before elaborating on our main insights from the different arenas covered here at SenseCy, we would like to first summarize three of the main trends we observed in 2015.

Firstly, when reviewing 2015, we recommend paying special attention to the evolving world of ransomware and new applications of this type of malware, such as Ransomware-as-a-Service (RaaS), and ransomware targeting cloud services, as opposed to local networks and more.

Secondly, throughout 2015, we witnessed cyber-attacks against high-profile targets attributed to ISIS-affiliated hackers and groups. One such incident was the January 2015 allegedly attack against the YouTube channel and Twitter account of the U.S. Central Command (CENTCOM).

Thirdly, 2015 revealed a continuing interest in the field of critical infrastructure among hackers. Throughout the year, we witnessed multiple incidents of critical infrastructure firms allegedly targeted by hackers, prompting periodic analyses addressing the potential vulnerabilities of critical sectors such as energy, water, and more. Taking into consideration the advanced capabilities and high-level of understanding of such systems required to execute such attacks, many security firms and experts are confident that these attacks are supported by nation-state actors.

Insights

The following are several of our insights regarding activities in different cyber arenas this past year:

Islamic Hacktivism

During 2015, we detected several indications of anti-Israel cybercrime activity on closed platforms frequented by Arabic-speaking hackers. It will be interesting to see if these anti-Israel hacktivists that usually call to deface Israeli websites or carry out DDoS attacks will attempt to incorporate phishing attacks, spamming methods and tools into their arsenals. Notwithstanding, Islamic hacktivism activity continues unabated, but without any significant success.

Trade on Russian Underground Forums

The prominent products currently traded during 2015 on Russian underground forums are ransomware programs and exploits targeting Microsoft Office. With regard to banking Trojans, we did not notice any major developments or the appearance of new Trojans for sale. The PoS malware field has not yielded any new threats either, in contrast to the impression given by its intensive media coverage.

Mobile malware for Android devices is on the rise as well, with the majority of tools offered being Trojans, but we have also detected ransomware and loaders.

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.

Exploits and exploit kits on the Russian underground
Exploits and exploit kits on the Russian underground

The English-Language Underground

Our analysis of password-protected forums revealed that exploits were the best-selling products of 2015. This comes as no surprise, since exploits are a vital part of almost every attack.

The Darknet made the headlines on multiple occasions this year, mostly owing to databases that were leaked on it and media reports recounting FBI activities against Darknet users. Furthermore, this year saw increased activity by the hacking community on the Darknet, manifested in dedicated markets for the sale of 0-day exploits and the establishment of several new hacking forums.

Sales of hacking tools in the English-language underground
Sales of hacking tools in the English-language underground

The Iranian Underground

With regard to Iranian threat actors, 2015 was a highly prolific year, with attack groups making headlines around the world. Delving deeper into the Iranian underground, we uncovered several interesting trends, some more clear than others.

One main development in 2015 was the persistent interest in critical infrastructure, with underground forum members sharing and requesting information related to industrial control systems and other related components. With Iranian actors becoming increasingly drawn to this field, we assess that this trend will remain relevant in 2016 as well.

Another growing phenomenon is the stunted life cycles of Iranian cyber groups, many with a life-span of just several months. This trend makes it difficult to monitor the different entities active in the Iranian cyber arena and their activities. To understand the constant changes in this realm, this short life cycle trend must be taken into consideration and the Iranian cyber arena continuously monitored.

That said, we must not overlook one of the most prominent characteristics of Iranian attack groups – confidentiality. With attacks attributed to Iranian actors becoming more sophisticated and high-profile, we believe that the divide between medium-level practices of malicious activity and alleged state-sponsored activity by attack groups will remain pronounced.

Screenshot from the IDC-Team forum showing, among other things, the list of “Hottest Threads” and “Most Viewed Threads” on the forum
Screenshot from the IDC-Team forum showing, among other things, the list of “Hottest Threads” and “Most Viewed Threads” on the forum

ISIS – Cyber-Jihad

On the other side of the Arab-speaking cyber world, we can find ISIS and its evolving cyber activities. There is disagreement between intelligence firms and cyber experts about the cyber offensive capabilities of the Islamic State. In addition, there is a high motivation among hackers that identify with the group’s fundamentalist agenda to carry out cyber-attacks against Western targets, especially against those countries actively involved in the war against the group in Iraq and Syria.