{ "family": "sharer", "sample_count": 1, "category": "trojan", "description": "

Executive Summary

\nSharer (often detected as Worm.P2P.Sharer or Trojan.Sharer) represents a family of legacy worms specifically engineered to exploit the decentralized nature of Peer-to-Peer (P2P) file-sharing networks (such as eMule, Kazaa, Limewire, or BitTorrent). By masquerading as highly desirable, pirated content, Sharer tricks users into downloading and executing the malware, subsequently hijacking the user's P2P client to distribute itself to thousands of other victims.\n\n

Infection Vector and Technical Capabilities

\nThe primary infection vector is entirely reliant on user deception. The malware is uploaded to P2P networks with enticing, frequently changing filenames (e.g., \"Windows_10_Crack.exe\", \"Photoshop_Keygen.exe\", or titles of recently released movies/music).\n\nUpon execution, Sharer focuses on rapid, automated propagation:\n\n\n

Threat Assessment

\nWhile the prominence of traditional P2P networks has declined in favor of streaming services, the tactic remains viable on modern torrent networks. A Sharer infection exposes the corporate network to significant legal liability (due to the active distribution of pirated/malicious files) and serves as an open door for more severe, secondary malware infections.\n\n

Remediation and Eradication

\n", "cta": "Published by the SystemHelpdesk team.", "aliases": [ "Worm.P2P.Sharer", "Trojan.P2P", "Win32/Sharer" ], "enrichment_level": "expert-seo", "faq": [ { "@type": "Question", "name": "What is Sharer and what threat category does it belong to?", "acceptedAnswer": { "@type": "Answer", "text": "Sharer is classified as a Trojan. Documented across security telemetry, it is engineered to execute unauthorized operations, establish persistent footholds on target endpoints, and facilitate malicious campaigns targeting enterprise and individual environments." } }, { "@type": "Question", "name": "How does Sharer establish persistence and evade defensive controls?", "acceptedAnswer": { "@type": "Answer", "text": "Sharer typically establishes persistence through registry run keys, scheduled tasks, or service installations, while evading signature-based antivirus solutions through code obfuscation, memory injection, or anti-analysis sandbox checks." } }, { "@type": "Question", "name": "What are the essential incident response steps for mitigating a Sharer compromise?", "acceptedAnswer": { "@type": "Answer", "text": "Security teams responding to Sharer should immediately isolate affected endpoints from the network, perform memory triage to capture volatile forensic artifacts, audit registry and startup persistence mechanisms, revoke exposed user credentials, and restore systems from verified, clean backups." } }, { "@type": "Question", "name": "What secondary payloads and staging behaviors are commonly associated with Worm.P2P.Sharer?", "acceptedAnswer": { "@type": "Answer", "text": "Worm.P2P.Sharer frequently operates as a loader or dropper designed to establish a foothold before downloading and executing secondary high-impact malware payloads. Depending on the threat actor's objectives, these dropped modules can range from ransomware and banking injects to modular infostealers and remote management backdoors." } }, { "@type": "Question", "name": "How can security operations teams effectively detect and hunt for Worm.P2P.Sharer across enterprise endpoints?", "acceptedAnswer": { "@type": "Answer", "text": "Defenders should hunt for Worm.P2P.Sharer by deploying behavioral endpoint detection and response (EDR) rules that monitor suspicious process spawning (such as cmd.exe or powershell.exe spawned from office documents or temporary directories), anomalous outbound network connections from non-browser binaries, and unauthorized modifications to Windows Run keys and scheduled task registries." } } ], "faq_count": 5, "mitre_attack": [ "T1566", "T1059", "T1105" ], "cisa_advisory": null, "last_updated": "2026-10-15", "type": "Worm / P2P", "target_industries": [ "Global / Opportunistic" ], "motivation": "Opportunistic", "threat_actors": [ "Unknown / Cybercriminal" ], "target_geographies": [ "Global" ], "attack_stage": [ "execution", "persistence" ], "ecosystem": [ "windows_pe" ], "is_emerging": false, "mitre_attack_detail": [ { "id": "T1566", "name": "Phishing", "tactic": "Initial Access" }, { "id": "T1059", "name": "Command and Scripting Interpreter", "tactic": "Execution" }, { "id": "T1105", "name": "Ingress Tool Transfer", "tactic": "Command and Control" } ], "containment_steps": [ "Sever network connectivity for the flagged endpoint to terminate persistent command-and-control (C2) communication channels and stop Sharer from retrieving secondary stage payloads.", "Capture process memory triage to detect and terminate malicious threads injected by Sharer into legitimate system processes such as explorer.exe or svchost.exe.", "Audit Windows Registry Run keys (HKCU\\Software\\Microsoft\\Windows\\CurrentVersion\\Run) and Task Scheduler entries to locate and purge Sharer persistence hooks.", "Deploy updated enterprise EDR detection signatures and conduct an out-of-band endpoint scan to isolate dropped binaries and staged payloads.", "Rotate all credentials, domain user passwords, and session cookies active on the system during the Sharer execution timeframe." ], "what_to_avoid": [ "Do not assume the incident is resolved simply because an antivirus tool removed the initial Sharer dropper; always verify that secondary payloads and persistence hooks have been eradicated.", "Avoid logging in with Domain Admin or privileged credentials on a machine suspected of running Sharer until memory triage is complete.", "Do not delay host isolation; automated lateral movement and credential dumping can occur within minutes of initial execution." ], "target_platforms": [ "Windows 11", "Windows 10", "Windows 7" ] }