{
  "family": "delfile",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nDelfile (short for \"Delete File\") is a generic classification for a destructive Trojan whose primary function is the systematic deletion or corruption of critical system files, user data, or specific applications. Unlike ransomware, which encrypts files for extortion, Delfile variants are purely destructive (wipers). They are often deployed as a final payload by advanced threat actors to destroy forensic evidence, sabotage operations, or render the infected system completely unbootable.\n\n<h3>Infection Vector and Technical Capabilities</h3>\nDelfile variants are typically deployed post-compromise. An attacker will utilize initial access vectors (like phishing or RDP brute-forcing) to gain administrative privileges before executing the destructive payload to maximize the damage radius.\n\nUpon execution, Delfile focuses on rapid, irreversible destruction:\n<ul>\n<li><strong>Targeted Deletion:</strong> The malware is often configured to iterate through the hard drive, specifically targeting user documents (`.docx`, `.pdf`, `.xls`), database files, and backups.</li>\n<li><strong>System Sabotage:</strong> To render the system unbootable, Delfile will target the `C:\\Windows\\System32` directory, deleting critical DLLs, the Boot Configuration Data (BCD), or the Master Boot Record (MBR).</li>\n<li><strong>Anti-Recovery (Wiping):</strong> Sophisticated variants do not simply delete the file pointer; they overwrite the data blocks on the hard drive with zeroes or random garbage data (secure wiping) to prevent data recovery using forensic tools.</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nA Delfile infection is a catastrophic security incident resulting in immediate and often irreversible data loss. It is designed to cause maximum operational downtime and sabotage, severely impacting business continuity.\n\n<h3>Incident Response and Remediation</h3>\n<ul>\n<li><strong>Immediate Power Off (Hard Stop):</strong> If a Delfile infection is suspected (e.g., files are rapidly disappearing), immediately perform a hard power off (pull the plug) on the affected machine. Do not execute a normal shutdown, as the malware may trigger further deletion routines during the shutdown sequence.</li>\n<li><strong>Forensic Data Recovery:</strong> Do not attempt to boot the affected drive. Image the drive offline and utilize specialized forensic data recovery tools to attempt to salvage any files that were not securely overwritten.</li>\n<li><strong>Rebuild from Offline Backups:</strong> The only reliable remediation for a destructive wiper is a complete bare-metal rebuild of the system utilizing known-good, offline backups that were inaccessible to the malware.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Trojan.Delfile",
    "Wiper.Delfile",
    "Trojan.KillFiles",
    "Destructive.Win32"
  ],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Delfile and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Delfile is classified as a Ransomware. 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 Delfile establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Delfile 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 Delfile compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Delfile 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 cryptographic algorithms and file targeting techniques does Trojan.Delfile employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Trojan.Delfile typically leverages hybrid cryptographic architectures combining symmetric stream or block ciphers (such as AES-256 or ChaCha20) for rapid file encryption with asymmetric algorithms (such as RSA-2048 or Curve25519) to securely protect the session keys. It aggressively targets sensitive file extensions including corporate documents, databases, virtual disks, and backups while systematically executing commands to delete Volume Shadow Copies (vssadmin delete shadows /all /quiet) and disable system recovery options."
      }
    },
    {
      "@type": "Question",
      "name": "Are decryptors available for Trojan.Delfile, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for Trojan.Delfile depends on whether security researchers or law enforcement (such as the No More Ransom initiative) have recovered the master private keys or discovered flaws in its key generation routines. Victims should never pay the extortion demand, as payment fuels criminal operations without guaranteeing file restoration. The recommended recovery procedure entails isolating infected hosts, conducting forensic disk imaging, identifying the root access vector, and restoring validated systems from immutable offline backups."
      }
    }
  ],
  "faq_count": 5,
  "mitre_attack": [
    "T1485",
    "T1561",
    "T1489"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-10-15",
  "type": "Trojan / Wiper (Destructive)",
  "target_industries": [
    "Healthcare",
    "Critical Infrastructure",
    "Enterprise"
  ],
  "motivation": "Financial Extortion",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ],
  "attack_stage": [
    "defense_evasion",
    "impact"
  ],
  "ecosystem": [
    "windows_pe"
  ],
  "is_emerging": false,
  "mitre_attack_detail": [
    {
      "id": "T1485",
      "name": "Data Destruction",
      "tactic": "Impact"
    },
    {
      "id": "T1561",
      "name": "Disk Wipe",
      "tactic": "Impact"
    },
    {
      "id": "T1489",
      "name": "Service Stop (Forcefully stopping AV services)",
      "tactic": "Impact"
    }
  ],
  "containment_steps": [
    "Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Delfile from spreading laterally or encrypting network-attached storage (NAS) and shared SMB volumes.",
    "Preserve volatile system memory (RAM capture) on a representative endpoint before attempting a reboot or power-down, as Delfile symmetric encryption keys or uncompiled payload components may still reside in memory.",
    "Audit process execution logs and terminate active scripting interpreters (e.g. PowerShell, CMD, WScript) or commands executing 'vssadmin.exe delete shadows' or 'wbadmin' used by Delfile to inhibit recovery.",
    "Investigate the initial compromise vector (such as exposed RDP instances, spearphishing attachments, or vulnerable edge gateways) and enforce an immediate credential reset for all compromised Active Directory accounts.",
    "Restore critical assets and databases exclusively from verified, air-gapped, or immutable offline backups once the Delfile binary and related persistence hooks are eradicated."
  ],
  "what_to_avoid": [
    "Do not restart or power cycle infected systems prematurely; doing so destroys volatile RAM encryption keys and may trigger bootloader locking logic embedded in Delfile.",
    "Avoid negotiating or paying the extortion demand without prior forensic evaluation and consultation with incident response specialists, as payment does not guarantee data recovery.",
    "Do not connect clean backup drives or external storage to the affected network until Delfile eradication is completely verified."
  ],
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}