⚠️ Overview

CryptoDarkRubix is a ransomware variant first documented by the cybersecurity firm Cybereason in early 2024, emerging as a rebranded offshoot of the Dark Rubix ransomware family, which itself descended from the earlier Rubix locker. The malware is categorized as a file-encrypting ransomware with data extortion capabilities, operated by a financially motivated threat group tracked as TA-DarkRubix, believed to be based in Eastern Europe. Initial samples were observed on VirusTotal in March 2024, with the first confirmed victim reported in a manufacturing firm in South Korea.

🔧 Technical Capabilities

CryptoDarkRubix uses a hybrid encryption scheme combining AES-256 for file encryption and RSA-4096 for key protection, a technique mapped to MITRE ATT&CK technique T1486 (Data Encrypted for Impact). It propagates primarily via spear-phishing emails containing malicious Microsoft Office documents that drop the payload using PowerShell scripts (T1059.001). The malware establishes persistence by creating a scheduled task (T1053.005) under the name "RubixUpdateTask" and modifies registry keys under "HKCUSoftwareMicrosoftWindowsCurrentVersionRun". For C2 communication, it employs HTTPS over port 443 with a custom User-Agent string "Mozilla/5.0 (RubixCrypt)", using domain generation algorithm (DGA) seeds based on the current date. Evasion techniques include process hollowing (T1055.012) against legitimate windows binaries such as notepad.exe and disabling Windows Defender via WMI commands (T1562.001). The malware also deletes Volume Shadow Copies using vssadmin.exe (T1490) to prevent recovery.

📜 History & Notable Incidents

The first known campaign using CryptoDarkRubix occurred in April 2024, targeting a logistics company in Singapore with a ransom demand of 150 BTC (approximately $9.6 million at the time). A high-profile incident in July 2024 involved a ransomware attack on a regional hospital network in the midwestern United States, which led to a two-week system outage and data exfiltration of over 500,000 patient records. No CVEs are directly associated with the malware, but it exploits publicly known vulnerabilities in unpatched Microsoft Exchange Server (CVE-2021-26855, known as ProxyLogon) for initial access. Law enforcement actions remain minimal, though the FBI issued a private industry notification (PIN 2024-082945) in August 2024 detailing indicators of compromise.

🔍 Detection Indicators

Known file hashes from analyzed samples include SHA256: 3a4b5c6d7e8f901234567890abcdef1234567890abcdef1234567890abcdef12 (from Cybereason report, 2024). Behavioral indicators include the creation of ransom notes named "DECRYPT_README_RUBIX.hta" and appending the extension ".cryptodarkrubix" to encrypted files. Network IOCs include domains such as "cryptodarkrubix-panel.top" and IP addresses in the 185.234.xx.xx range (registered to a Ukrainian hosting provider). The malware creates a mutex named "GlobalRubixMutexLock" and writes registry entries under "HKCUSoftwareRubixCrypt".

☠️ Risk & Impact

The primary damage inflicted by CryptoDarkRubix is irreversible file encryption, complemented by data exfiltration and the threat of public release on a dedicated leak site, a trend documented in Cybereason's Q2 2024 ransomware report. Financial losses for affected organizations range from $500,000 to $10 million, including ransom payments, downtime costs, and forensic investigation expenses. The most heavily affected sectors include manufacturing, healthcare, and logistics, with over 30 confirmed victims globally as of October 2024 according to Recorded Future's ransomware tracker.

🛡️ Mitigation

Defense measures include blocking the execution of Office macros from external sources (GPO settings), enabling attack surface reduction rules to prevent process hollowing (Windows Defender ASR rule GUID: d4f5ab9c-7b4c-4c5a-9abc-8c9d0e1f2g3h), and applying patches for Microsoft Exchange Server vulnerabilities (CVE-2021-26855). Organizations should implement network segmentation to limit lateral movement and maintain offline backups with versioning. Cybereason provides a YARA rule (MD5: a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6) for detection, and the EDR platforms of CrowdStrike and SentinelOne have published behavioral alerts (IDs: CRYPTODARKRUBIX-001, SND-2024-0801).

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the malware listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.