{
  "family": "evillocker",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nEvilLocker is a highly destructive Ransomware family designed to extort financial payment from victims by encrypting their critical data. It is known for its rapid deployment and aggressive encryption routines, prioritizing the immediate and widespread encryption of local and network-mapped drives to cause maximum operational disruption before security teams can respond.\n\n<h3>Infection Vector and Technical Capabilities</h3>\nEvilLocker is typically distributed via weaponized email attachments (spear-phishing) or deployed by threat actors who have purchased RDP credentials from Initial Access Brokers (IABs) and manually executed the payload within the compromised network.\n\nUpon execution, EvilLocker initiates a standard but devastating attack sequence:\n<ul>\n<li><strong>Volume Shadow Copy Deletion:</strong> Before encryption begins, the ransomware executes commands (e.g., `vssadmin.exe Delete Shadows /All /Quiet`) to destroy local system backups and recovery points, ensuring the victim cannot easily restore their files using Windows features.</li>\n<li><strong>Strong Cryptography:</strong> It utilizes strong encryption algorithms (often a combination of AES for file encryption and RSA for key encryption) to encrypt documents, databases, images, and archives. The encrypted files are usually appended with a specific, unique extension (often `.evil` or a randomized string).</li>\n<li><strong>Ransom Note Generation:</strong> A text or HTML file is dropped in every directory containing encrypted files. This note provides instructions on how to purchase cryptocurrency (usually Bitcoin) and contact the attackers to obtain the decryption key.</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nAn EvilLocker infection is a critical security incident resulting in immediate and often catastrophic loss of data availability. The destruction of local backups means that without secure, offline backups, organizations face a stark choice between massive data loss or paying a criminal extortion demand.\n\n<h3>Incident Response and Remediation</h3>\n<ul>\n<li><strong>Immediate Network Severance:</strong> The infected endpoint must be immediately disconnected from the corporate network, Wi-Fi, and any VPNs to prevent the ransomware from propagating to mapped network drives and cloud storage sync folders.</li>\n<li><strong>Preserve Memory (Do Not Reboot):</strong> If possible, capture a forensic image of the system's RAM before powering it down, as the decryption key might temporarily reside in volatile memory.</li>\n<li><strong>Eradication and Restoration:</strong> Paying the ransom is strongly discouraged. The only reliable remediation strategy is a complete bare-metal wipe of the infected systems and a full restoration from secure, air-gapped backups.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Ransom.EvilLocker",
    "Win32/Filecoder.Evil",
    "Trojan-Ransom.Win32.EvilLocker"
  ],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Evillocker and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Evillocker 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 Evillocker establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Evillocker 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 Evillocker compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Evillocker 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 Ransom.EvilLocker employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Ransom.EvilLocker 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 Ransom.EvilLocker, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for Ransom.EvilLocker 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",
    "T1490",
    "T1082",
    "T1027"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-10-15",
  "type": "Ransomware",
  "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": "T1490",
      "name": "Inhibit System Recovery (Behaviorally blocking the deletion of backups)",
      "tactic": "Impact"
    },
    {
      "id": "T1082",
      "name": "System Information Discovery",
      "tactic": "Discovery"
    },
    {
      "id": "T1027",
      "name": "Obfuscated Files or Information",
      "tactic": "Defense Evasion"
    }
  ],
  "containment_steps": [
    "Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Evillocker 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 Evillocker 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 Evillocker 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 Evillocker 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 Evillocker.",
    "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 Evillocker eradication is completely verified."
  ],
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}