{
  "family": "sohanad",
  "sample_count": 11,
  "category": "trojan",
  "description": "Worm:Win32/Sohanad is a widespread, classic computer worm that gained notoriety for spreading aggressively via removable drives (USB flash drives) and popular Instant Messaging (IM) clients, notably Yahoo Messenger. Its primary function was to propagate itself, degrade system security settings, and often act as a downloader for secondary adware or trojan payloads.<br><br><b>Understanding the Sohanad Worm</b><br>To an end-user, a Sohanad infection often manifested as a sudden inability to access the Registry Editor or Task Manager, and the appearance of strange, hidden executable files on their USB drives. For security analysts, Sohanad is a textbook example of a highly successful network-bridging worm. By relying on physical media (USBs), it could easily cross air-gapped networks or jump between home and corporate environments.<br><br><b>Propagation and Persistence Mechanics</b><br>Sohanad spreads primarily by exploiting the Windows AutoRun feature (`T1091`). When an infected USB drive is inserted into a vulnerable PC, Windows automatically executes the `autorun.inf` file, which points to the hidden Sohanad executable on the drive. Once executed, the worm copies itself to the Windows system folder (`%SystemRoot%`) and creates multiple Registry Run keys (`T1547.001`). Crucially, to protect itself, Sohanad actively modifies the Registry to disable `taskmgr.exe`, `regedit.exe`, and the 'Show Hidden Files' option in Windows Explorer (`T1562.001`). It then actively polls for newly inserted USB drives, infecting them to continue the cycle. Additionally, it historically hooked into Yahoo Messenger to send malicious links to the victim's contact list.<br><br><b>Indicators of Compromise & Impact</b><br>The impact is rapid, widespread lateral movement across an organization, degraded security controls, and potential secondary payload delivery. Incident responders will observe a sudden spike in EDR alerts relating to `autorun.inf` execution and unauthorized modifications to critical Windows policies (disabling Task Manager). Network logs may show the worm downloading secondary payloads from hardcoded IPs.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Sohanad and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Sohanad 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 Sohanad establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Sohanad 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 Sohanad compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Sohanad 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 Sohanad?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Sohanad 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 Sohanad across enterprise endpoints?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Defenders should hunt for Sohanad 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": [
    "T1091",
    "T1547.001",
    "T1562.001",
    "T1564.001"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1091",
      "name": "Replication Through Removable Media",
      "tactic": "Lateral Movement"
    },
    {
      "id": "T1562.001",
      "name": "Impair Defenses: Disable or Modify Tools (Task Manager/Regedit)",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1547.001",
      "name": "Boot or Logon Autostart Execution: Registry Run Keys",
      "tactic": "Persistence"
    },
    {
      "id": "T1564.001",
      "name": "Hide Artifacts: Hidden Files and Directories",
      "tactic": "Defense Evasion"
    }
  ],
  "containment_steps": [
    "Immediately disable the Windows AutoRun/AutoPlay feature globally across the enterprise via Group Policy (GPO) to halt further propagation.",
    "Quarantine all known infected endpoints and mandate that any USB drives connected to them be considered compromised and formatted.",
    "Deploy a script via GPO to revert the malicious registry changes (re-enabling Task Manager, Regedit, and Hidden Files).",
    "Scan all network file shares, as the worm may attempt to copy itself to mapped drives in addition to physical USBs."
  ],
  "what_to_avoid": [
    "Do not insert a suspected infected USB drive into an analysis machine unless AutoRun is strictly disabled and you are operating in a contained environment.",
    "Avoid relying solely on file deletion; if the registry modifications are not reverted, the user will still be unable to see hidden files or use Task Manager."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ],
  "attack_stage": [
    "execution",
    "persistence"
  ],
  "ecosystem": [
    "windows_pe"
  ],
  "is_emerging": false,
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows 7"
  ]
}