{
  "family": "disabler",
  "sample_count": 10,
  "category": "ransomware",
  "description": "Trojan:Win32/Disabler (or generic **Disabler** heuristics) represents a critical class of malware specifically engineered to actively hunt, cripple, and terminate endpoint security software (Antivirus, EDR, Windows Defender) prior to the execution of a primary payload (like ransomware or a rootkit). Disablers act as the vanguard of a sophisticated attack, 'clearing the path' so the subsequent malware can operate undetected.<br><br><b>Understanding Disabler Malware</b><br>To an end-user, the infection might manifest as a sudden, unexplained red 'X' on their antivirus icon, or a failure to open the Windows Security Center. For a security analyst, a Disabler alert is an emergency. If a Disabler successfully executes, the endpoint is completely blind and defenseless. Modern ransomware (like LockBit or Conti) heavily relies on custom Disabler modules (often leveraging BYOVD - Bring Your Own Vulnerable Driver techniques) to bypass enterprise EDR.<br><br><b>Execution and Impairment Mechanics</b><br>A Disabler is typically dropped by an Initial Access Broker trojan (`T1105`). Upon execution (`T1204.002`), it attempts to escalate privileges to `SYSTEM`. Once achieved, it employs multiple techniques to blind the endpoint (`T1562.001`). It will forcefully terminate the processes of known security vendors (e.g., `MsMpEng.exe` for Defender). It modifies the Windows Registry to disable real-time protection, tamper protection, and cloud-delivered protection. Advanced Disablers will load a vulnerable, signed driver (BYOVD) to gain kernel-level (`Ring 0`) access, allowing them to forcefully unload the kernel-mode drivers used by EDR solutions to monitor process creation and memory injection.<br><br><b>Indicators of Compromise & Impact</b><br>The impact is the complete loss of endpoint visibility and protection, almost always followed immediately by a severe compromise. The primary IoC is an avalanche of EDR 'Tamper Protection' alerts, followed by the EDR sensor suddenly dropping offline. System logs (`Event ID 7036`) will show the unexpected termination of the Antivirus service. Analysts should look for the dropping of unexpected `.sys` files (drivers) in the `C:\\Windows\\System32\\drivers` directory.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Disabler and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Disabler 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 Disabler establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Disabler 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 Disabler compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Disabler 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 Disabler employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Disabler 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 Disabler, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for Disabler 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": [
    "T1562.001",
    "T1112",
    "T1489",
    "T1068"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1562.001",
      "name": "Impair Defenses: Disable or Modify Tools (Terminating AV/EDR)",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1068",
      "name": "Exploitation for Privilege Escalation (BYOVD Attacks)",
      "tactic": "Privilege Escalation"
    },
    {
      "id": "T1112",
      "name": "Modify Registry (Disabling Defender settings via Policy)",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1489",
      "name": "Service Stop (Forcefully stopping AV services)",
      "tactic": "Impact"
    }
  ],
  "containment_steps": [
    "Instantly isolate the endpoint from the network; if a Disabler is active, a ransomware deployment is likely imminent.",
    "Do not rely on the local EDR agent for containment if the Disabler was successful; isolate the machine at the switch/firewall level.",
    "Capture a memory dump (RAM) immediately. The Disabler module and the subsequent payload are likely active in memory even if the EDR is blind.",
    "Perform a deep forensic review to identify the vulnerable driver (BYOVD) used to bypass kernel protections and block its hash enterprise-wide."
  ],
  "what_to_avoid": [
    "Do NOT assume the endpoint is safe if you simply restart the antivirus service; the malware maintains persistence and will disable it again.",
    "Avoid relying solely on automated remediation; a successful Disabler means the automated tools have been compromised."
  ],
  "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,
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}