{
  "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": [
    {
      "@type": "Question",
      "name": "What is Ransomkd and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Ransomkd 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 Ransomkd establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Ransomkd 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 Ransomkd compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Ransomkd 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 Ransomkd employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Ransomkd 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 Ransomkd, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for Ransomkd 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": [
    "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": [
    "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"
  ]
}