{
  "family": "hermes",
  "sample_count": 7,
  "category": "ransomware",
  "description": "Ransom:Win32/Hermes is a highly significant ransomware family in cybersecurity history. First appearing around 2017, Hermes gained international infamy when it was utilized by the North Korean state-sponsored threat group **Lazarus Group** as a distraction payload during the $60 million cyber-heist against the Far Eastern International Bank (FEIB) in Taiwan. Crucially, the source code and cryptographic logic of Hermes form the direct foundation of the devastating **Ryuk** ransomware, one of the most successful 'Big Game Hunting' ransomware families in existence.<br><br><b>Understanding the Hermes Threat</b><br>To an infected user, the outcome is catastrophic: documents, databases, and critical files are suddenly encrypted, their filenames appended with `.hermes` (or similar extensions). A ransom note (usually a `UNIQUE_ID_DO_NOT_REMOVE.html`) demands cryptocurrency. For a security operations center (SOC), a Hermes detonation represents the final stage of a highly targeted, prolonged network compromise, often indicating the presence of advanced persistent threat (APT) actors.<br><br><b>Execution and Encryption Mechanics</b><br>Hermes is rarely distributed via mass spam. It is deployed manually by attackers after gaining deep network access (often via compromised RDP or VPNs) (`T1133`). Once deployed via PsExec or batch scripts (`T1569.002`), the ransomware first executes a `.bat` script containing commands (like `vssadmin.exe Delete Shadows /All /Quiet`) to destroy Windows Volume Shadow Copies (`T1490`). It then rapidly encrypts targeted files (`T1486`) using a combination of RSA-2048 and AES-256 cryptography. A unique characteristic of Hermes (inherited by Ryuk) is its ability to bypass files related to the operating system boot process to ensure the victim can still boot the computer to read the ransom note.<br><br><b>Indicators of Compromise & Impact</b><br>The impact is severe operational downtime and potential permanent data loss. The primary IoC is the massive, rapid modification of files across the hard drive and network shares, appending the `.hermes` extension. Host-based IoCs include EDR alerts for the mass deletion of shadow copies and the execution of specific batch files used to launch the encryptor. Because it is associated with APT activity, discovering Hermes means the entire network architecture is likely compromised.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1490",
    "T1486",
    "T1133",
    "T1569.002"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1486",
      "name": "Data Encrypted for Impact (RSA/AES encryption)",
      "tactic": "Impact"
    },
    {
      "id": "T1490",
      "name": "Inhibit System Recovery (Deleting Volume Shadow Copies via batch scripts)",
      "tactic": "Impact"
    },
    {
      "id": "T1569.002",
      "name": "System Services: Service Execution (Deploying via PsExec)",
      "tactic": "Execution"
    },
    {
      "id": "T1133",
      "name": "External Remote Services (Initial access vector, e.g., RDP)",
      "tactic": "Initial Access"
    }
  ],
  "containment_steps": [
    "Instantly isolate the infected endpoint from the network to halt the encryption process, explicitly disconnecting it from mapped network shares.",
    "Do NOT reboot the machine immediately; capture a live memory dump (RAM) first, as forensic analysis may recover the AES key from memory.",
    "Assume total network compromise. The deployment of Hermes/Ryuk indicates attackers have had domain admin access for days or weeks.",
    "Wipe the infected systems and restore data from secure, immutable offline backups."
  ],
  "what_to_avoid": [
    "Do not pay the ransom. Paying funds criminal enterprises (and potentially state-sponsored actors), and there is no guarantee the attackers will provide a working decryption tool.",
    "Avoid reconnecting the machine to the network until a full forensic investigation has identified and closed the initial entry vector (e.g., compromised VPN credentials)."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}