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System Specific Encryption

Arete Analysis

Ransomware variants like Phobos, Dharma or CryLock are file level encryption. The TA gains access to the system, copies specific encryption executables onto the systems then runs the executables to encrypt the files. The results are files with a new extension appended to the old file name. Sometimes it’s a random sequence of numbers and letters (e.g. *.nocv) or a specific tag (e.g. *[CryLockDecrypt@****.com][1].[ID-*****- COM]). System specific encryption generates a unique key per encrypted system. The ransom note or the file extension may indicate an “ID” that would be different on each system.

CryLock Scanner & Decryptor

Communication preference: Email usually aol.com, protonmail.com, or cock.li domains

Average ransom payment: $27,000 – $500,000

Preferred currency: Bitcoin (BTC)

Decryptor Received: 95% of the time. Certain variants of Phobos and Dharma will attempt to re-extort a second payment if a large discount is negotiated.

Watch out: Phobos, Dharma, and CryLock are a two-step process. The TA will first send a “scan- ner” tool that needs to be run on every infected system. The scanner will look for the public keys used to encrypt the files, then write that informa- tion to a corresponding .txt or .ini file. Those cor- responding files need to be sent to the TA in or- der to generate a decryptor. The TA in return will send the decryptors. The two-step process adds significant overhead due to the running of mul- tiple tools on the infected system as well as the delay with communicating via email. On average after making a payment for the decryptor, clients are who are infected with Phobos are down for approximately 11 days whereas clients who are infected with Dharma experience downtime of about 7.75 days. The high number of days can be attributed to the two-step process and multiple email communications.

Notes: Negotiating with the Phobos and Dhar- ma group can be tricky. These variants are Ransom-as-a-Service (RaaS) model so you’re not dealing with the same core group of people as you would with variants like Ryuk (or now Conti). Negotiating with RaaS groups can also create confusion and complexities with a different operator responding to each email. The groups who deploy these variants also look for exploiting publicly accessible Remote Desktop Protocol (RDP). Disable external access to RDP to lessen the chance of being infected by this variant.

System Specific Encryption with a Universal Option

Ransomware variants like Sodinokibi are file level encryption with a unique ID per system. Once the TA gains access to the network, they release their Sodinokibi ransomware throughout the environment. The systems are infected with a unique randomly generated file extension per system. Their ransom notes are usually within a text file and explain what happened, including if any data was exfiltrated. The group is very organized and can often share information about their victim’s networks including domain information, infected systems, and any stolen data.

Sodinokibi Decryptor

Communication preference: TOR Website via chat room. The ransom note contains a link to the TOR site as well as a unique key to gain access to a private chat room where the negotia tions occur.

Average ransom payment: $170,000

Preferred currency: Monero (XMR)

Decryptor received: 100% of the time. Sodin offers a general decryptor which requires the victim to collect the file extensions from all of their infected systems. This can be very tedious once the payment is made, the victim can input any number of file extensions into the input box on the TOR site to generate a decryptor. Sodin will keep that private room open for 30 days after payment.

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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.

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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