{
  "family": "wlock",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nWlock is a destructive Ransomware variant (often functioning as a \"Screen Locker\"). Its primary objective is to extort money from the victim by either encrypting user files or completely locking the user interface (the Windows desktop), demanding a cryptocurrency payment (or prepaid vouchers) in exchange for restoring access to the system or data.\n\n<h3>Infection Vector and Technical Capabilities</h3>\nWlock is typically distributed via spam campaigns with malicious attachments, malvertising, or brute-force RDP (Remote Desktop Protocol) attacks against internet-facing servers.\n\nUpon execution, Wlock forcefully denies access to the system:\n<ul>\n<li><strong>Screen Locking Mechanism:</strong> If operating as a locker, Wlock modifies the Windows Registry (often hijacking the `Winlogon\\Shell` key) to load its own full-screen application instead of the standard `explorer.exe` desktop. This completely prevents the user from accessing the Start menu, taskbar, or any files.</li>\n<li><strong>File Encryption (Crypto-variant):</strong> If operating as a standard crypto-ransomware, it rapidly enumerates the hard drive and network shares, encrypting documents, photos, and databases utilizing strong encryption algorithms (like AES or RSA). The original files are deleted, leaving only the encrypted versions.</li>\n<li><strong>Extortion Demand:</strong> The malware displays a persistent, intimidating ransom note (often claiming to be from law enforcement or utilizing aggressive countdown timers) instructing the victim on how to purchase cryptocurrency and transfer the funds to the attacker.</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nA Wlock infection is a critical security incident resulting in an immediate denial of service and potential total data loss. It completely halts business operations on the infected endpoint.\n\n<h3>Incident Response and Remediation</h3>\n<ul>\n<li><strong>Network Isolation:</strong> Disconnect the infected machine immediately to prevent the ransomware from spreading to mapped network drives or other devices on the LAN.</li>\n<li><strong>Safe Mode Bypass (For Lockers):</strong> If Wlock is acting purely as a Screen Locker, booting the machine into \"Safe Mode with Command Prompt\" or using an offline bootable rescue disk can often bypass the locker application, allowing an administrator to remove the malicious registry keys and delete the executable.</li>\n<li><strong>Data Restoration (For Crypto):</strong> If files have been encrypted, paying the ransom is strongly discouraged, as it funds criminal enterprises and does not guarantee a decryption key. The only reliable remediation is a complete wipe and re-image of the system, followed by data restoration from secure, offline backups.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Ransomware.Wlock",
    "Trojan.Ransom.Wlock",
    "WinLock"
  ],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Wlock and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Wlock 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 Wlock establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Wlock 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 Wlock compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Wlock 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 Ransomware.Wlock employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Ransomware.Wlock 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 Ransomware.Wlock, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for Ransomware.Wlock 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": [
    "T1486",
    "T1489",
    "T1547.004"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-10-15",
  "type": "Ransomware / Screen Locker",
  "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": "T1486",
      "name": "Data Encrypted for Impact",
      "tactic": "Impact"
    },
    {
      "id": "T1489",
      "name": "Service Stop (Forcefully stopping AV services)",
      "tactic": "Impact"
    },
    {
      "id": "T1547.004",
      "name": "Boot or Logon Autostart Execution: Winlogon Helper DLL (Shell hijacking)",
      "tactic": "Persistence"
    }
  ],
  "containment_steps": [
    "Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Wlock 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 Wlock 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 Wlock 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 Wlock 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 Wlock.",
    "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 Wlock eradication is completely verified."
  ],
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}