{
  "family": "sfone",
  "sample_count": 332,
  "category": "trojan_generic",
  "description": "Trojan:Win32/Sfone is a highly targeted information stealer and stealthy backdoor engineered to quietly exfiltrate sensitive data while maintaining long-term persistence on compromised endpoints.<br><br><b>Understanding Sfone</b><br>To the victim, Sfone provides zero visual indication of infection. For threat intelligence analysts, Sfone represents a specialized espionage tool. Unlike noisy botnets, it is often utilized in targeted campaigns where the primary goal is the prolonged, silent extraction of proprietary documents, keystrokes, and active directory credentials rather than immediate financial extortion.<br><br><b>Execution and Evasion Strategies</b><br>Sfone is typically delivered via highly tailored spearphishing campaigns containing weaponized Office documents. Upon execution, it performs extensive environment checks, querying the registry for known sandbox artifacts and halting execution if a debugger is detected. Once validated, it drops a heavily obfuscated DLL into the <code>%AppData%</code> directory. It achieves persistence by employing DLL Search Order Hijacking against legitimate system executables or creating a hidden scheduled task. It communicates with its Command-and-Control (C2) server using custom encryption over HTTPS to blend in with normal corporate web traffic.<br><br><b>Indicators of Compromise & Impact</b><br>The impact of Sfone is a total compromise of confidentiality. Incident responders should monitor for anomalous, persistent HTTPS connections originating from legitimate processes (like <code>svchost.exe</code>) to unknown or newly registered IP addresses. Memory forensics is critical to extract the decrypted Sfone payload and identify the specific C2 domains. Dropped, highly entropic <code>.dat</code> files in the user profile directory (used to stage stolen data before exfiltration) are strong IoCs.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1547.001",
    "T1056.001",
    "T1573",
    "T1497",
    "T1055.001"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1055.001",
      "name": "Process Injection: Dynamic-link Library Injection",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1573",
      "name": "Encrypted Channel",
      "tactic": "Command and Control"
    },
    {
      "id": "T1056.001",
      "name": "Input Capture: Keylogging",
      "tactic": "Collection"
    },
    {
      "id": "T1547.001",
      "name": "Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder",
      "tactic": "Persistence"
    },
    {
      "id": "T1497",
      "name": "Virtualization/Sandbox Evasion",
      "tactic": "Defense Evasion"
    }
  ],
  "containment_steps": [
    "Instantly isolate the endpoint from the network to sever the attacker's interactive, remote-control session.",
    "Capture a full forensic memory image of the machine to extract the decrypted Sfone payload and its C2 configuration.",
    "Force a global password reset for all user accounts that accessed the machine, assuming total endpoint and credential compromise.",
    "Rebuild the operating system from a known-clean image, as Sfone is known to deploy secondary rootkits to maintain access."
  ],
  "what_to_avoid": [
    "Do not leave the machine connected to the network during triage; the attacker has live access and will likely destroy evidence or move laterally.",
    "Avoid relying solely on static signatures, as Sfone is frequently re-packed and obfuscated for each targeted campaign."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}