{
  "family": "ransomkd",
  "sample_count": 3,
  "category": "ransomware",
  "description": "Ransom:Win32/Ransomkd is a generic heuristic detection used by antivirus engines to identify executables that exhibit behavior typical of **Cryptographic Ransomware**. Because it is a generic detection, it does not identify a specific, well-known family (like Ryuk or LockBit), but rather flags the *action* of mass file encryption occurring on the system.<br><br><b>Understanding Ransomkd (Generic Ransomware)</b><br>To an end-user, the impact is devastating: personal documents, photos, and databases are suddenly inaccessible, appended with an unknown file extension, and a ransom note (often a `.txt` or `.hta` file) appears on the desktop demanding cryptocurrency payment for the decryption key. For a security analyst, a 'Ransomkd' detection means a severe breach has already progressed to its final, most destructive stage.<br><br><b>Execution and Encryption Mechanics</b><br>The delivery method varies (malspam, RDP brute-forcing, exploiting unpatched vulnerabilities). Upon execution, the malware establishes persistence (`T1547.001`) and immediately begins iterating through the file system and mapped network drives (`T1083`). It employs the Windows CryptoAPI or embedded cryptographic libraries (like AES or RSA) to rapidly encrypt files matching specific extensions (e.g., `.docx`, `.sql`, `.pdf`) (`T1486`). Crucially, to prevent easy recovery, the malware actively inhibits system recovery by deleting Volume Shadow Copies (`vssadmin.exe delete shadows`), disabling Windows Recovery Environment (`reagentc.exe /disable`), and clearing event logs (`T1490`).<br><br><b>Indicators of Compromise & Impact</b><br>The impact is total loss of data availability and severe business interruption. Host-based IoCs include EDR alerts for mass file modification events (high I/O activity), the execution of `vssadmin` or `bcdedit` commands by unknown processes, the appearance of ransom notes (`RESTORE_FILES.txt`), and the modification of file extensions across user directories. Network IoCs may include connections to Tor gateways or hardcoded IP addresses for key exchange prior to encryption.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1083",
    "T1486",
    "T1490",
    "T1547.001"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1486",
      "name": "Data Encrypted for Impact",
      "tactic": "Impact"
    },
    {
      "id": "T1490",
      "name": "Inhibit System Recovery (Deleting Shadow Copies)",
      "tactic": "Impact"
    },
    {
      "id": "T1083",
      "name": "File and Directory Discovery (Scanning for files to encrypt)",
      "tactic": "Discovery"
    },
    {
      "id": "T1547.001",
      "name": "Boot or Logon Autostart Execution",
      "tactic": "Persistence"
    }
  ],
  "containment_steps": [
    "IMMEDIATELY physically disconnect the infected endpoint from the network (pull the Ethernet cable/disable Wi-Fi) to prevent the ransomware from encrypting shared network drives and lateral movement.",
    "Do not immediately reboot the machine; if the encryption process is ongoing, a reboot might finalize the destruction or trigger further payloads. Capture a live memory dump if possible to potentially recover encryption keys.",
    "Identify the specific strain of ransomware (by analyzing the ransom note or file extensions) and check resources like 'No More Ransom' to see if a free decryptor exists.",
    "Restore the affected systems from secure, offline backups (e.g., tape drives or immutable cloud storage) that were not accessible from the infected network."
  ],
  "what_to_avoid": [
    "Do not pay the ransom; it funds criminal enterprises and there is no guarantee the attackers will provide a working decryption tool.",
    "Avoid reconnecting the machine to the network until it has been completely wiped and rebuilt from a known-clean image."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}