{
  "family": "killmbr",
  "sample_count": 1,
  "category": "ransomware",
  "description": "Trojan:Win32/Killmbr (or KillDisk) is a classification for destructive 'Wiper' malware whose primary function is to obliterate the Master Boot Record (MBR) (`T1561.002`) and/or the Master File Table (MFT). Unlike ransomware, which encrypts data to extort money, the sole purpose of a wiper is sabotage—to render the host completely unbootable and the data permanently unrecoverable.<br><br><b>Understanding Killmbr (Destructive Wiper)</b><br>To an end-user, the machine suddenly blue-screens and upon reboot, displays a 'Missing Operating System' or a custom, mocking message from the attackers. For a SOC analyst, a wiper attack is a worst-case scenario, often deployed by nation-state actors (like the NotPetya or HermeticWiper attacks) to disrupt critical infrastructure or deployed by ransomware gangs to cover their tracks if a victim refuses to pay.<br><br><b>Execution and Destruction Mechanics</b><br>To execute its destructive payload, Killmbr *must* obtain high-level administrative or SYSTEM privileges (`T1068`). Once elevated, it uses low-level Windows APIs (like `DeviceIoControl`) to open a direct handle to the physical hard drive (e.g., `\\\\.\\PhysicalDrive0`). It then overwrites the first sector (Sector 0, the MBR) with zeroes or random garbage. Advanced variants will also overwrite the MFT and the partition tables. When the machine inevitably reboots (often forced by the malware), the BIOS cannot locate the bootloader, effectively bricking the OS.<br><br><b>Indicators of Compromise & Impact</b><br>The impact is a total loss of system availability and data. Host-based IoCs include EDR alerts for a process attempting to open a handle to `\\\\.\\PhysicalDrive0` with write permissions. Attackers often use living-off-the-land tools like `vssadmin.exe` to delete shadow copies before initiating the wipe. Once the wipe occurs, the primary indicator is the physical inability to boot the machine.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1561.002",
    "T1529",
    "T1485"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1561.002",
      "name": "Disk Wipe: Disk Structure Wipe (Overwriting the MBR to prevent booting)",
      "tactic": "Impact"
    },
    {
      "id": "T1485",
      "name": "Data Destruction (Overwriting files and the MFT)",
      "tactic": "Impact"
    },
    {
      "id": "T1529",
      "name": "System Shutdown/Reboot (Forcing a restart to trigger the unbootable state)",
      "tactic": "Impact"
    }
  ],
  "containment_steps": [
    "If a wiper attack is suspected and currently in progress, IMMEDIATELY power off the machine (hard shutdown) to halt the overwriting process.",
    "Do not attempt to reboot the machine normally; boot from a forensic live USB or WinPE environment to assess the damage.",
    "If only the MBR is overwritten, use tools like `bootrec /fixmbr` (though advanced wipers destroy the partition table as well).",
    "Restore the system from an offline, read-only backup."
  ],
  "what_to_avoid": [
    "Do not perform a graceful shutdown if you suspect a wiper; simply pull the power cord to preserve whatever data hasn't been overwritten yet.",
    "Avoid relying solely on Volume Shadow Copies for recovery, as wipers almost universally delete these first."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}