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Darkside Ransomware: Caviar Taste on Your Big-Game Budget

Arete Analysis

Summary

Explore Darkside ransomware, an operation utilizing sophisticated tactics to target high-revenue organizations. Arete’s threat intelligence data reveals high ransom demands, extensive business downtime, and universal data exfiltration.  

By all appearances, the proprietors of Darkside ransomware mean business. 

With their sights set on organizations with US$4M+ in revenue, they’re about high-value, big-game targets and they’ve got the skills and experience to bring in some big hauls.

The Darkside group demonstrates seasoned experience, polished business acumen, and an ability to quickly respond to both negative and positive stimuli within their sphere of market influence. They exhibit similarities to notable ransomware operations, such as LockBit and REvil, and they take an outwardly aggressive posture toward the security industry, taunting companies like BitDefender and Coveware. 

Statistical data on Darkside ransomware from Arete engagements 

The information below is based on Darkside events that the Arete IR team has investigated since November 2020. Our incident response and data analytics practices work together to track key data points and collect statistics on variants for every ransomware engagement.

Sectors of clients affected by this threat:

Professional Services | Manufacturing

  • Average Ransom Demand: US $6,527,402.02

  • Highest Ransom Demand: US $10,054,804

  • Lowest Ransom Demand: US$3,000,000

  • Average business downtime: 5 days

  • Data exfiltration observed in 100 percent of cases

Key observations

Based on the Arete Cyber Threat Intelligence (CTI) team’s assessments:

Darkside ransomware operators are likely conducting long-tail reconnaissance of the victim environment for up to two (2) weeks prior to deploying their payloads. 

  • The earliest known point of malicious activity for a select event was noted when forensic discovery indicated installation of the MetaSploit framework on the victim’s domain controller fifteen (15) days prior to enterprise-wide, automated deployment of Darkside. 

Yes, we expect Darkside to be big-game hunters. Forbes quoted them as saying they will target “only those who can afford to pay.” Their recruitment advertisements echo this assertion. 

  • Darkside proprietors and operators come from an established pedigree. 

  • They are transparent in their description of operational mistakes and they renumerate operators for lost revenue. 

  • They taunt BitDefender and Coveware directly with aggressive and forthright assertions of their intent. 

  • As recently as December 27, 2020, a Russian-speaking cybercriminal actor using the handle ‘darksupp’ invited media outlets and data recovery organizations to follow a new “Press Center” section at the Darkside “name-and-shame” leak site. Darksupp allegedly stated that this press center would enable media and recovery firms to ask questions about recent attacks while also giving recovery organizations access to a dedicated chat room, where they could enroll in a “loyalty program” for discounts on data decryption. 

  • The group has underwritten their aspirations with a substantial surety bond (approx. US$350k) and assert that they are willing to increase their guarantee to inspire further confidence in the right partners. 

  • Their first and now exclusive appearance on XSS (reboot of DamageLab) along with exploitation of their endorsements/acceptance from known Russian-speaking actors underpins the Arete CTI team’s current assessment of their maturity and client knowledge. 

  • On November 10, 2020, a Russian-speaking cybercriminal actor using the handle ‘darksupp’ announced the launch of an official recruitment effort for affiliates to participate in the Darkside Ransomware-as-a-Service (RaaS) affiliate program. 

  • Darksupp received a forum-public favorable review on XSS from actor Quake3 (aka LockBit), proprietor of the LockBit RaaS platform. 

  • The proprietor(s) behind the ‘darksupp’ persona tout seasoned experience with and feature influence from notable ransomware operations, such as LockBit and REvil. 

  • Darkside operator affiliates are likely using Whitebit (e.g., Whitebit[.]com) to cash out, given observed wallet transactions and ledger analysis by Arete. 

Detailed information

On August 8, 2020, operators of the Darkside ransomware announced their malware in a press release on the dark web. They stated that they had created their ransomware because they could not find the perfect product for their needs and had made millions of dollars by partnering with other well-known ransomware groups. In the same release, they also said they would not be targeting the healthcare, education, non-profit, and government sectors.  

On November 11, 2020, Darkside announced their RaaS model, inviting partners and affiliates to work with them. They also announced the development of a distributable data storage system, calling out the use of servers in Iran and unrecognized republics to prevent victim organizations from taking down their operations.

Figure 1. Darkside announces their service.


Figure 2. Darkside announcement of their RaaS product, distributed storage system, and invitation to partners and affiliates to work with them.

After this announcement, multiple news outlets began reporting that the group was using servers in sanctions countries like Iran. In response, the Darkside group updated their storage announcement on November 15, 2020, stating: 

  • The storage system is still in the planning stages and has not yet launched. 

  • They are not citizens of Iran, and leaked company data is not and will not be hosted in Iran. 

  • They are still considering where to host the leaked data, but it would not be in a region on the sanctions list. 


Figure 3. Darkside makes an updated announcement, that they will think where to host leaked data on servers that are not in sanctions countries.

The above business model makes total sense from the threat actors’ perspective. If the data were stored on servers in regions on the U.S. Treasury Department’s Office of Foreign Asset Control (OFAC) sanctions list, the actors would be unable to obtain ransom payments from victims.

The Arete CTI team and other researchers in the community found that the group has been advertising their services on well-known Russian hacker forums, with posts written in Russian. 


Figure 4. Darkside group advertising on a well-known hacking forum (Source: SentinelOne)


Figure 5. A Google translation of Darkside advertisement on a well-known Russian hacking forum (Source: SentinelOne)

Based on language analysis, a native Russian-language speaker wrote the posts. What’s more, the group’s ransomware is designed to avoid infecting systems in Commonwealth of Independent States (CIS) countries, including Russia. In the past, other Eastern European threat actor groups have done the same to try to avoid getting in trouble with local law enforcement agencies. The Arete CTI team also conducted blockchain analysis of previous ransom payments and did not find any ties between sanctioned entities/money service businesses (MSBs) and Darkside money-laundering operations. 

As leaders in the community and especially in the current COVID-19 climate, we need to join forces to properly inform the public without causing worldwide panic and help ensure our clients’ quick recovery from attacks and return to normal business operations. If a company were to make a rash decision about ransom payments based on negligent reporting, it could prevent file restoration and ultimately, shutter a business and cost employees their livelihood. 

Darkside high-level technical overview

While tactics, techniques, and procedures (TTPs) may vary amongst operators, it’s important to note that Darkside caters to semi-exclusive affiliates, likely of Russian or Eastern European origin. They likely pool their technical experience — both successes and failures — from this exclusive cultural enclave to orchestrate their intrusions and execute on their objective as outlined below: 

  • Darkside ransomware is primarily geared toward Windows systems, however, the proprietor ‘darksupp’ claims the ability to develop payloads that also target Linux OS variants. 

  • We have observed the builder module screens for the control panel, and we are aware of the existence of Linux ELF-executable payloads. We assess this to be true, with high confidence. 

  • Given observed use of MetaSploit and potentially other Offensive Security Tool (OST) frameworks — always contingent on operator/affiliate preference — it’s likely that Darkside ransomware operators leverage these same tools to enumerate vulnerabilities of victim networks, where externally facing systems of interest are exposed, to establish initial access. 

  • We observed actors pivoting from having Administrator RDP sessions on the Domain Controller, to accessing another privileged account to access a file server. Thus, it’s highly likely that their two weeks in the environment afforded them precision-targeting abilities. They took their time hunting. 

  • On November 25, 2020, ‘darksupp’ claimed to have launched a content delivery network (CDN) for storing and delivering compromised data exfiltrated from victims of Darkside ransomware. The actor also claimed to be developing a second version of the ransomware and intends to provide support for distribution using dynamic-link library (.dll) and PowerShell scripts (.ps1) for deployment. 

    • We have observed Darkside operators manually enumerating and exfiltrating data using a combination of RDP access and their own copy of QTBrowser, 7zip. This culminates in a direct upload of files to both PrivatLab and MegaUpload cloud hosting, under cover of Web/HTTPS sessions, which are difficult to sift in many cases for less mature organizations. \

    • This manual methodical exfiltration occurred over the span of several hours. 

    • 7zip archives were named after data/folder names enumerated and temporarily stored in root temp directory (e.g., C:Temp, C:Temp1, C:Temphr{archive}.7z). 

  • We observed Darkside payload (e.g., azure_agent.exe.exe) staged on the domain controller in a network-shareable folder (e.g., C:WindowsIMEazure), followed by the establishment of a scheduled task (e.g., WindowsSYSVOLdomainPolicies{L0NGMGU1D}UserPreferencesScheduledTasks) set with Group Policy and instructing hosts to obtain and execute the payload. This resulted in a fully automated enterprise-wide deployment less than 24 hours after data was exfiltrated. 

Security Recommendations  

  1. Implement a sophisticated endpoint detection and response (EDR) solution that will rely on behavior analysis — not just malware signatures — and have tamper-proof capabilities. 

  2. Implement multifactor authentication (MFA). 

  3. Implement an email security solution to detect and protect against known and unknown threats. 

  4. Hunt for unusual remote desktop protocol (RDP) connections. 

  5. Use Group Policy Software Restriction Policies (SRP) to prevent users from executing Windows executable filetypes (e.g., .exe, .dll, .hta, .bat, .scr) from the AppDataLocalTemp path of Office365, Microsoft Word, Excel, and Outlook. Alternatively, also inspect C:Users[current user]AppDataRoamingMicrosoft as it’s another popular method that achieves the same results. 

  6. Implement and regularly test an off-site backup solution. 

Appendix

Indicator

Role

C:\Windows\IME\azure

File path of DC where Darkside payload was staged.

F:\temp

File path of staged 7zip archives (.7z) prior to exfiltration

F:\temp1

File path of staged 7zip archives (.7z) prior to exfiltration

F:\temphr

File path of staged 7zip archives (.7z) prior to exfiltration

Windows\SYSVOL\domain\Policies\{LONGMGU1D}\User\Preferences\ScheduledTasks

Path of Scheduled Task on Domain Controller for deployment of Darkside payload via Group Policy.

Indicator

Role

azure_agent.exe.exe

Darkside Payload

README.3a43168b.TXT

Darkside Ransomware Note – README.{random_string}.TXT

enc.exe

Darkside Payload

idfoodsf.exe

Darkside Payload

Indicator

Role

6d134cdf470f03707ad481b617e67b9018f92f72a0e2fb3e6cc9f2ab17ac1439

Darkside Payload

06cfe7f5d88e2f7adda6d8333ca8b302debb22904c68a942188be5730e9b3c8

Darkside Payload

243dff0fc80a049f4fb3729f8b8def0fce29768f345c88ee1069e22b0ae60

Darkside Payload

0839aabe5fd63b16844a27b3c586c02a044d119010a1a40ee4035501c34eae0d

Darkside Payload

Indicator

Role

www[.]privatelab[.]com

Manual Data Exfiltration – Cloud Upload

www[.]mega[.]nz

Manual Data Exfiltration – Cloud Upload

Bitcoin Wallet Address  

bc1qkk8z69uxkrxdeuwlkvlk89p7qnr6cefa4aeq7p  

Leak Site  

hxxps://Darksidedxcftmqa[.]onion  


Complete advertisement from the Darkside group on a popular Russian hacking forum (Full translation from Russian to English)  

————- [Welcome to Darkside] ————–> Кто мы? ——————————  

Мы продукт нацеленный только на крупные корпорации. Можно детальнее прочесть тут: https://www.forbes.com/sites/daveywinder/2020/08/23/beware-of-the-dark-side-a-sinister-new-1-million-cybersecurity-threat-Darkside-ransomware/ https://bbc.com/news/technology-54591761https://www.wired.com/story/ransomware-gone-corporate-Darkside-where-will-it-end/ https://www.bleepingcomputer.com/news/security/Darkside-ransomware-hits-north-american-real-estate-developer/  

Кого мы ищем? 

 ——————————  

Ограниченное количество стабильных и адекватных партнеров, кто понимает зачем нужно выгружать данные, что такое бэкапы и как их удалять, русскоговорящих, со средними выплатами от 400к. Кого мы НЕ ищем?  

—————————— 

 Англоговорящих личностей. 

  • Сомнительных личностей, сотрудников секретной службы и аналитиков ИБ компаний. 

  • Тех, кто ставит дедики и занимается деятельностью отличимой от поставки сетей. 

  • Любые темы и предложения отличимые от этого поста. 

  • Желающих обучиться пентестингу и зарабатывать миллионы. 

  • Любителей ставить 100кк выкупа за 3.5 сервера. 

О софте? 

—————————— 

Мы готовы предоставить партнерам: 

  • Windows [full ASM, salsa20 + rsa 1024, i/o, собственная реализация salsa и rsa, fast / auto (улучшенный space) / full, имперсонализация токена для работы с шарами, раб столом, освобождение занятых файлов, изменение прав на файлы, arp scanner, завершения процессов, сервисов, drag-and-drop и много другого]. 

  • Linux [C++, chacha20 + rsa 4096, многопоточен (в том числе Hyper-threading, аналог i/o на windows), поддержка урезанных сборок ос (esxi 5.0+), fast / space, настройка каталогов и много другого]. 

  • Админ панель [full ajax, автоматический прием Bitcoin, Monero, генерация win / lin билдов с указанием всех параметров (процессы, сервисы, папки, расширения…), отстук ботов и детальная статистика по результативности компании, автоматическое распределение и вывод средств, саб–аккаунты, онлайн чат и множество другого]. 

  • Leak site [скрытые посты, поэтапная публикация данных таргета и еще множество функционала]. 

Все решения уже проверены и доделаны, мы сами работаем своим софтом и не писали его на продажу / аренду, в отличие от многих продуктов.То чего нам не хватало в работе с другими партнерскими программами — мы реализовали у себя.
Правила? 

—————————— 

  • Следующие сферы запрещены:
    – Медицина (Больницы, госпитали).
    – Образование (Университеты, школы).
    – Государственный сектор (муниципалитеты, любые гос органы).
    – Некоммерческие организации (благотворительные фонды, ассоциации). 

  • Запрещены любые действия, которые наносят репутационный урон имиджу продукта. 

  • Запрещена любая работа по СНГ (в том числе Грузии, Украине). 

  • Запрещена передача аккаунта третьим лицами. 

Какой процент? 

——————————  

От 25% до 10%. В софте динамическая система рейта. Чем больше выплата, тем меньше % партнерки и наоборот.Так же возможен стабильный рейт, это обсуждается. Как попасть?  

—————————— 

 Пройти собеседование, показать свою работу и выплаты, ответить на необходимые вопросы.Но для начала написать в ЛС. При этом указать: 

  • Свой опыт работы. 

  • С какими партнерскими программами работали. 

  • Диапазон сумм выкупа. Минимум, максимум, средняя. 

  • Работаете сами или в команде. 

  • TOX или jabber. 

Если вам не ответили, то вы не подошли, спамить в теме не нужно. 

Рассматриваем ли мы доступы в сети? 

——————————  

Да, USA от 400kk, с предложениями можно отписать в ЛС, написав сайт, сферу деятельности компании и контакт. Если компания интересна – с вами свяжутся. Какие гарантии?  

——————————  

Депозит в 20 BTC (~305k на момент написания) на xss.is. Если у вас будут супер предложения, мы с удовольствием его поднимем, вплоть до 1кк и более. 

Translation to English: 

Who are we looking for? 

 ——————————  

A limited number of stable and adequate partners who understand the importance of exfiltrating data, awareness of backups and how to delete them, Russian-speaking, with average payouts of 400k.  

Who are we NOT looking for?  

—————————— 

  • English-speaking personalities. 

  • Suspicious individuals, employees of the secret service and analysts of information security companies. 

  • Those who only setup RDP access or do other things other than deploy on networks. 

  • Any topics and suggestions different from this post. 

  • Those who want to learn pen-testing and earn millions. 

  • Those who think they can demand US$100M in ransom for 3.5 servers. About software? 

——————————  

We are ready to provide partners with:  

  • Windows payloads [full ASM (assembly language), I/O, custom implementation of the Salsa20 and RSA-1024 ciphers, fast / automated / full encryption, token impersonation for accessing shared network drives, process termination to encrypt open files, file permission modification, ARP scanning tool, the drag-and-drop UI/UX features, and much more) 

  • Linux payloads [C++, ChaCha20 + RSA-4096, multithreading (including hyper-threading, an analogue of the Windows I/O system), support of stripped-down OS versions (ESXI 5.0 and up), fast [encryption] / space [overwrite], catalog adjustment, and many other things]. 

  • Admin panel [ajax, automatic transaction processing for Bitcoin, Monero, generation of Windows/Linux builds with selectable parameters (processes, services, folders, and extensions), bots will report detailed statistics on the company’s performance, ability to create sub-accounts, online chat and much more]. 

  • Leak site [ability to hide posts, allows for detailed disclosures of compromised data, and much more]. All solutions have been tested and we work with our own software and did we did not produce it simply for sale/rent, unlike many products. In our program, we’ve implemented everything we wanted, but did not find in other affiliate programs. 

Rules? 

 ——————————  

  1. The following areas are prohibited: 

  • Healthcare (clinics and hospitals).  

  • Education (universities and schools).  

  • The public sector (municipal services and public agencies).  

  • Non-profit organizations (charitable foundations and associations).  

Any actions that can damage the product reputation are prohibited.  

Do not target systems in the CIS (this includes Georgia and Ukraine).  

Sharing accounts is not allowed.  

What’s the percentage/share of profits?  

——————————  

From 25% to 10%. The software has a dynamic rate system. The higher the payout, the lower the% of the affiliate program and vice versa.  

A stable rate is also possible, this is being discussed.  

How to get?  

——————————  

Pass an interview, show your work and payments, answer the necessary questions. First, send us a message. Indicate:  

  • Your previous experience. 

  • What other programs you’ve worked.

  • Your range of previous closed payments; minimum, maximum, average. 

  • Your preferences on working alone or with a team. 

  • Provide your TOX or Jabber contact. 

If we don’t answer you, then you weren’t the right fit, don’t spam us about it in the topic thread. Will we consider network accesses?  

——————————  

Sure, provided it’s a U.S. company with US$400M+ in revenue.  

Solicit your offer for consideration; provide company website, line of business, and your contact details. If we’re interested, we’ll contact you.  

What guarantees?  

——————————  

We made a deposit of 20 BTC (~ 305,000 USD) with forum escrow at XSS. If you make an awesome partnership proposal, we may raise that deposit to 1M+ to instill further confidence.  

——————————   

Note: Edited for clarity and readability 

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Article

Top 9 Security Controls for SMBs

In today’s complex cyber threat landscape, small and medium-sized businesses (SMBs) should implement a layered, multi-pronged approach to security. Here are some proven, effective controls to consider:

1.        Implement MFA for All Users
Multi-factor authentication (MFA) is an effective and accessible way to protect sensitive data, comply with regulatory standards, and prevent unauthorized access to critical systems. By ensuring that users not only use a password but also a secure token, an organization can significantly reduce phishing attempts, credential stuffing attacks, and ransomware incidents. MFA should be enabled for email, VPN, and critical system access.

2.        Update Patch Management Programs
A modern patching program should include policies and mechanisms to manage software updates in a timely manner. Patching efforts should address not just operating system updates, but also commonly utilized software within the environment. An active patching plan aims to reduce the mean time to patch and provide metrics on existing patch efforts. In the event of a high-severity vulnerability, a mature patching program should also be able to identify the risks and exposure for a given set of systems based on the average time to patch. This helps stakeholders make informed decisions when a new exploit is released.

3.        Leverage a Properly Managed Endpoint Detection and Response (EDR) Tool
With real-time threat detection and advanced visibility, endpoint detection and response (EDR) solutions can enhance an organization’s ability to detect and investigate potential malicious activity, including ransomware, lateral movement, fileless attacks, and more. Effective management of EDR should include proper configuration, regular agent updates, and established procedures for responding to alerts.

4.        Enhance EDR with Frontline Incident Intelligence
While EDR solutions are an important component of a security program, threat actors are continually adapting their techniques to evade detection, and as a result, standard detection methods may not always identify emerging threats or novel attack behaviors. To strengthen protection, organizations can supplement EDR tools with custom detection rules informed by incident response data. These rules can help identify indicators of compromise observed during cyber incidents, providing an additional layer of visibility beyond traditional detections.

Arete Bloktd℠ illustrates this approach by transforming threat intelligence and malware analysis into curated detection rules for EDR tools. Applying frontline intelligence to security tools can result in earlier detection, less investigative burden, and a more confident response. 

5.        Create and Continuously Test an Incident Response (IR) Plan
An incident response plan can help an organization effectively identify, respond to, and recover from a cybersecurity incident while minimizing disruption and downtime. An IR plan defines clear roles, escalation paths, communication strategies, and decision frameworks for both internal and external teams. To be effective, these plans should be regularly tested with post-incident reviews or tabletop exercises involving key stakeholders.

6.        Maintain Encrypted and Tested Data Backups
In the case of a cyberattack, backups can help organizations maintain business continuity, support ransom negotiations with threat actors, and contribute to a timely and successful recovery. Encrypting backups makes it more difficult for threat actors to access or alter them, and regular testing ensures they remain accessible during a security incident.

7.        Conduct Employee Security Awareness Training
Human error is a leading cause of cybersecurity incidents, and an organization’s employees are its first line of defense against cyber threats. Security awareness training reinforces the importance of data confidentiality, supports regulatory compliance, and helps employees recognize and understand red flags such as suspicious emails, malicious links, and social engineering attempts.

8.        Assess and Address Existing Risk and Vulnerabilities
To maintain a proactive approach to risk management and improve resilience, organizations should regularly assess existing vulnerabilities through expert-led Vulnerability Assessments, Penetration Testing, and Threat Hunting Assessments. These exercises can help identify security gaps, support regulatory compliance, and prevent potential incidents. During remediation, prioritize high-impact vulnerabilities and make a plan for periodic assessments.

9.        Apply Least-Privilege Access Controls
Employees should have access only to the systems, applications, and data necessary to perform their jobs. By removing unnecessary administrative privileges and regularly reviewing user permissions, organizations can reduce the risk of unauthorized access and limit the damage caused by compromised accounts or insider threats.

Organizations should regularly review their cybersecurity programs, stay informed about emerging threats, and evaluate whether their security controls are adapting to the evolving threat landscape.

Article

Ransomware Trends & Data Insights: August 2026

Although INC Ransom was the most active ransomware threat group observed in August 2026, overall activity remained relatively distributed across the threat landscape, with approximately 30 unique ransomware and extortion groups, including both established and newly emerged actors, observed during the month. Alongside INC Ransom, Storm, DragonForce, Qilin, and The Gentlemen were among the top five most active threat groups, underscoring the continued diversity and competitiveness of the ransomware ecosystem.

Figure 1. Activity from the top 5 threat groups in August 2026 

Throughout the month, analysts at Arete identified several trends behind the threat actors perpetrating cybercrime activities: 

  • August 2026 was a significant month for the emergence of new threat actors, with Arete identifying several previously untracked ransomware groups, including Storm, Dark Project, DireWolf, Morpheus, Orova, Spirals, Wallstreet Team, and Zawoo Team. This trend underscores the ongoing evolution of the threat landscape and the low barriers to entry for new cybercriminal operations. 

  • Arete observed a continued use of AI-enabled capabilities across the ransomware ecosystem during August. Similar to Fulcrumsec and Setra, the newly emerged Zawoo Team appears to leverage AI-assisted analysis of stolen data, publishing highly structured and detailed victim assessments on its data leak site (DLS). Additionally, both the Aurora and Storm ransomware groups have been observed utilizing AI-driven or AI-assisted chat representatives during victim communications. These developments suggest that threat actors are increasingly incorporating AI to enhance data analysis, automate victim engagement, and improve the effectiveness and scalability of extortion operations. 

  • In August, Arete also observed that despite sustained law enforcement disruption efforts, LockBit continues to demonstrate operational resilience, likely through the expansion of its affiliate ecosystem and the evolution of its tactics. Recent activity indicates an increased reliance on data theft and exfiltration-only operations, with observed victimology suggesting a notable focus on organizations within the financial sector. 

Sources

  • Arete Internal

Report

Arete's H1 2026 Crimeware Report

Explore intelligence and operational data from the frontlines of ransomware and extortion response as we detail the most significant trends and developments in the cyber threat landscape in the first half (H1) of 2026.

Article

WinRAR Path-Traversal Vulnerability Exploited in Ransomware Attacks

CISA has warned that CVE-2025-8088, a path-traversal vulnerability in WinRAR, is being exploited in ransomware attacks. The vulnerability allows attackers to use specially crafted archive files to place malicious executables in locations such as the Windows Startup folder, enabling code execution when the system restarts. WinRAR addressed this vulnerability in version 7.13, but exploitation has continued due to challenges in updating the software. CISA's updated KEV entry now specifically identifies the vulnerability as being used in ransomware attacks. 

What’s Notable and Unique

  • The vulnerability was initially exploited as a zero-day by the Russia-linked RomCom group, enabling malware execution at user logon and supporting credential theft, cyberespionage, and ransomware-related activities.

  • CVE-2025-8088 continues to be actively exploited by both government-backed and financially motivated threat actors. Observed campaigns have been attributed to Russian- and Chinese-linked groups targeting several organizations.

  • Phishing campaigns leveraging weaponized RAR attachments exploited CVE-2025-8088 to silently place malicious payloads in autorun locations using directory traversal and Alternate Data Streams (ADS). 

  • The widespread exploitation of CVE-2025-8088 highlights strong demand for effective WinRAR exploits, with multiple underground vendors previously supplying exploit capabilities to a diverse range of threat actors. One such vendor, zeroplayer, advertised a WinRAR exploit in July 2025. 

Analyst Comments

Organizations should immediately upgrade WinRAR to version 7.13 or later and conduct an enterprise-wide inventory to identify unmanaged installations. Given that WinRAR lacks automatic updates, Group Policy support, and integration with common enterprise patch management platforms, manual verification and remediation may be required to ensure all vulnerable instances are addressed. Security teams should also enhance defenses against archive-based phishing attacks by blocking or scrutinizing unsolicited compressed files, monitoring for suspicious file creation in Windows Startup directories, and detecting abuse of ADS. With CISA now linking CVE-2025-8088 to ransomware activity, organizations should treat remediation as a high priority and actively monitor for indicators of WinRAR-based exploitation across their environments.

Sources

  • CISA Adds Three Known Exploited Vulnerabilities to Catalog

  • WinRAR vulnerability being exploited in ransomware attacks, CISA warns