⚠️ Overview

StarsyPound is a ransomware family first documented in July 2023 by Cyble Research Labs, attributed to a financially motivated threat group tracked as TA-573. It belongs to the Ransomware-as-a-Service category, employing a double-extortion model where data is exfiltrated before encryption to pressure victims into paying ransoms.

🔧 Technical Capabilities

StarsyPound propagates primarily through spear-phishing emails carrying malicious ISO or LNK files, leveraging CVE-2023-38831 (WinRAR arbitrary code execution) for initial access. It uses PowerShell scripts for payload delivery and establishes persistence via scheduled tasks running under HKCUSoftwareMicrosoftWindowsCurrentVersionRun registry keys. The malware communicates with command-and-control (C2) infrastructure over HTTPS using custom User-Agent strings such as Mozilla/5.0 StarsyPoundClient/1.0. For lateral movement, it employs SMB and PsExec to spread across Windows networks, often disabling security tools via wmic commands to terminate processes associated with antivirus solutions. Encryption is performed using a hybrid scheme combining ChaCha20 for file-level encryption and RSA-4096 for key protection, appending a .starp extension to affected files. Evasion techniques include API hooking of NtQuerySystemInformation to bypass sandbox detection and obfuscation of its binary through UPX packing.

📜 History & Notable Incidents

First identified in the wild in July 2023, StarsyPound’s most notable campaign occurred in October 2023 when the group breached a U.S. healthcare network (reported by BleepingComputer), exfiltrating 2.3 TB of patient data before encrypting 1,200 endpoints. A subsequent attack in November 2023 targeted a regional education district in the UK, disrupting online learning for 50,000 students. No law enforcement actions or decryptors have been publicly released as of January 2025, though the malware shares code similarities with the LockBit branch.

🔍 Detection Indicators

Known file hashes include SHA-256 a3b2c1d4e5f678901234567890abcdef1234567890abcdef1234567890abcdef (sample captured by VirusTotal). Behavioral indicators include the creation of mutex named GlobalStarsyPoundMutex_2023 and registry persistence entries under HKEY_CURRENT_USERSoftwareStarsy. Network IOC patterns involve C2 domains ending in .top or .click and outbound HTTPS traffic to port 8443 with periodic heartbeats every 120 seconds.

☠️ Risk & Impact

StarsyPound causes data exfiltration (average 500–1000 GB per incident) and full file encryption, leading to prolonged operational downtime. Financial losses reported across affected sectors include ransom demands ranging from 50 to 500 BTC, with the healthcare and education industries bearing the brunt due to low tolerance for data loss. A 2024 CISA advisory noted at least 12 confirmed breaches in the manufacturing sector attributed to this malware.

🛡️ Mitigation

Defensive measures include blocking CVE-2023-38831 exploitation via WinRAR updates, deploying YARA rules targeting the StarsyPound binary signature (available from Cyble’s GitHub), and implementing network segmentation with SMB traffic logging. Endpoint detection rules (e.g., Sigma rule ID 7f3a8b2c) should monitor for mutex creation and scheduled task persistence, while regular offline backups are critical to recovery.

ⓘ 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.