GLOBAL RANSOMWARE ATTACKS IN 2020: THE TOP 4 VULNERABILITIES

Our team recently investigated the prominent ransomware attacks reported since the beginning of 2020 in order to draw general conclusions about these attacks and to reveal commonalities between them.  We also wanted to better understand the threat they pose and how to protect against it. While examining approximately 180 different ransomware incidents, we found that the most targeted sectors were Technology (11%), Government (10%), Critical Infrastructure (8.6%), Healthcare and Pharmaceutical (8%), Transportation (7%), Manufacturing (6%), Financial Services (5%) and Education (4%). It was also found that Sodinokibi/REvil, Maze and Ryuk are the most active ransomware strains.

A very interesting finding our investigation uncovered was that the operators behind these ransomware attacks commonly abused four notable vulnerabilities, that will be elaborately discussed in this blog post. This highlights the importance of timely installation of security updates as a defense mechanism to minimize the risk of ransomware and other malware attacks.

Here they are: The four top vulnerabilities abused in 2020 ransomware attacks (ordered from the most abused one):

  • CVE-2019-19781
  • CVE-2019-11510
  • CVE-2012-0158
  • CVE-2018-8453

Let’s take a closer look:

CVE-2019-19781

CVE-2019-19781 Characteristics

The CVE-2019-19781 vulnerability affects remote access appliances manufactured by Citrix, whose products are used by numerous organizations. The vulnerability was publicly disclosed at the end of December 2019 and fixed a month later. The vulnerability affects Citrix Application Delivery Controller (ADC), formerly known as NetScaler ADC. Successful exploitation of the vulnerability could allow an unauthenticated attacker to connect remotely and execute arbitrary code on the affected computer.

Since the vulnerability was disclosed, it was successfully exploited by threat actors in a significant number of incidents. In January 2020, security researchers reported the REvil gang leveraged the vulnerability in its attack against the Gedia Automotive Group. No technical details about the attack were disclosed, but from the information published by the attackers, it appears the company used the vulnerable products. The Ragnarok ransomware gang also exploited this vulnerability in January 2020. The attackers exploited the vulnerability to download scripts and scan the targeted system for computers vulnerable to the EternalBlue vulnerability.

In February 2020, the cloud company Bretagne Telecom reportedly suffered a cyber-attack by cybercriminals operating the DopplePaymer ransomware. The DopplePaymer gang stated it carried out the attack in the first half of January 2020, when a fix for the vulnerability had still not been released. This suggests the attackers discovered the vulnerability even earlier. At the end of March 2020, it was reported the MAZE ransomware gang had also leveraged the vulnerability in an attack on the cyber insurer company, Chubb.

In a different incident from the beginning of June 2020, it was reported that the IT services giant, Conduent, had also fallen victim to a MAZE gang ransomware attack. According to reports online, MAZE targeted a Citrix server of the company that was not patched or properly updated. On June 22, 2020, it was reported that the Indian conglomerate, Indiabulls, had suffered a cyber-attack carried out by the CLOP ransomware operators. Cyber security company Bad Packets reported that Indiabulls used Citrix NetScaler ADC VPN Gateway, which was vulnerable to CVE 2019-19781. However, the company did not confirm this vulnerability was exploited in the attack. Recently, the New Zealand CERT (CERT NZ) reported that many threat actors are leveraging this vulnerability, and the Nephilim ransomware gang may have also attempted to exploit it.

CVE-2019-11510

CVE-2019-11510 Characteristics

The CVE-2019-11510 vulnerability affects VPN Pulse Secure products. It allows attackers to remotely access the targeted network, remove multi-factor authentication protections and access the logs that contain cached passwords in plain text. Although the vulnerability has already been publicly disclosed for some time now and patched back in April 2020, many organizations have not yet patched it and remain exposed to attacks.

In recent months, the vulnerability was reportedly successfully exploited in a number of ransomware attack incidents. In two incidents, the attackers gained domain admin privileges and used an open-source remote access software, VNC, to perform lateral movement on the targeted network. Then, the attackers turned off security software and infected the system with the REvil ransomware. The most notable ransomware attack affected Travelex at the end of December 2019. The company did not patch its VPN solution, which allowed the REvil ransomware gang to carry out a successful attack that paralyzed the company’s systems for a number of weeks, persisting into 2020.

In another incident reported in April 2020, the IT systems of several hospitals and government entities in the US were infected with an unknown ransomware by nation-state threat actors. In addition, in June 2020, the operators of the Black Kingdom ransomware reportedly attempted to exploit the vulnerability as well.

CVE-2012-0158

CVE-2012-0158 Characteristics

The CVE-2012-0158 is an old vulnerability in Microsoft products, but is still one of the most exploited vulnerabilities in recent years, according to the US CERT. In December 2019, our team also reported that it is one of the top 20 vulnerabilities to be patched before 2020, based on the number of times it has been exploited by sophisticated cyber-attack groups operating in the world today. The vulnerability allows the attacker to remotely execute code on the victim’s computer through a specially crafted website, Office or .rtf document.

In recent months, security researchers reported exploitation attempts for the CVE-2012-0158 vulnerability in COVID-19-related attacks. The researchers reported attack attempts against medical and academic organizations in Canada. One of the campaigns included infection attempts with the EDA2 ransomware, a strain of a wider ransomware family, known as HiddenTear. The attackers used an email address that resembles and imitates the legitimate address of the World Health Organization. The phishing emails sent to the targeted organizations contained malicious files designed to exploit this vulnerability to execute code remotely and infect them with the ransomware. An additional phishing campaign attempted to infect victims from the above mentioned organizations with a ransomware dubbed RASOM.

CVE-2018-8453

CVE-2018-8453 Characteristics

The CVE-2018-8453 resides in the win32k.sys component of Windows, since it fails to properly handle objects in memory. A successful exploitation can allow an attacker to run arbitrary code in kernel mode, install programs; view, change, or delete data; or create new accounts with full user rights.

The Sodinokibi/REvil ransomware was first spotted exploiting CVE-2018-8453 in 2019 in multiple attacks in the Asia-Pacific region, including Taiwan, Hong Kong, and South Korea. In July 2020, it was reported that it was exploited again by the same ransomware gang against Brazilian-based electrical energy company Light S.A. The attackers first demanded a ransom of 106,870.19 XMR (Monero), and after the deadline has passed the ransom doubled to 215882.8 XMR, which amounts to approximately $14 million.

SUMMING UP: THE PATCHING PARADOX

In an ideal world, organizations would patch every new vulnerability once it’s discovered. In real-life, this is impossible. Security analysts responsible for vulnerability management activities face multiple challenges that result in what the industry calls “The Patching Paradox”: common sense tells you to keep every system up to date in order to be protected, but this is not possible due to limited resources, existence of legacy systems and slow implementation of patches. The goal of this analysis is to provide security professionals with an incentive to improve their patching management activities.

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.

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

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.

1
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.

2
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.

    3
    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