{
  "family": "crusis",
  "sample_count": 19,
  "category": "ransomware",
  "description": "Ransomware:Win32/Crusis (heavily associated with, and often an alias for, the notorious Crysis/Dharma ransomware family) is a highly prolific, human-operated ransomware variant. Unlike automated worms, Crusis is deployed manually by attackers who have already breached the network, typically via compromised Remote Desktop Protocol (RDP) endpoints.<br><br><b>Understanding Crusis</b><br>To an end-user, a Crusis infection is catastrophic. All files are encrypted, their extensions are changed (often appending the attacker's email address and a specific extension like `.crusis`, `.dharma`, or `.wallet`), and a ransom note (`FILES ENCRYPTED.txt`) is dropped on the desktop. For incident responders, Crusis signifies a severe perimeter breach. The attackers have likely been inside the network for days, elevating privileges, disabling backups, and exfiltrating data before manually executing the encryption payload.<br><br><b>Execution and Human-Operated Tactics</b><br>Crusis actors primarily gain initial access by brute-forcing or purchasing compromised RDP credentials (`T1133`). Once inside, they use legitimate administrative tools (living-off-the-land) and credential dumpers (like Mimikatz) to escalate privileges to Domain Admin. They disable antivirus services using tools like `Process Hacker` or uninstaller utilities (`T1562.001`). They aggressively target and delete Volume Shadow Copies (`vssadmin.exe Delete Shadows /All /Quiet`) and backup catalogs (`T1490`). Finally, the Crusis executable is pushed across the network via GPO or PsExec, encrypting files using strong AES/RSA cryptography (`T1486`).<br><br><b>Indicators of Compromise & Impact</b><br>The impact is a total halt of business operations and potential data extortion. EDR platforms must alert on anomalous RDP logins (especially off-hours or from foreign IPs), the execution of `vssadmin.exe`, and the mass renaming of files. The presence of the dropped executable (often named `payload.exe` or simply a random string) in the `%AppData%` or `%Temp%` directory is a key IoC.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1490",
    "T1059",
    "T1133",
    "T1562.001",
    "T1486"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1486",
      "name": "Data Encrypted for Impact",
      "tactic": "Impact"
    },
    {
      "id": "T1133",
      "name": "External Remote Services",
      "tactic": "Initial Access"
    },
    {
      "id": "T1490",
      "name": "Inhibit System Recovery",
      "tactic": "Impact"
    },
    {
      "id": "T1562.001",
      "name": "Impair Defenses: Disable or Modify Tools",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1059",
      "name": "Command and Scripting Interpreter",
      "tactic": "Execution"
    }
  ],
  "containment_steps": [
    "Instantly sever the infected endpoint and any associated servers from the network to halt the lateral spread of the encryption process.",
    "Identify and immediately disable the compromised RDP accounts or VPN profiles that the attackers used for initial access.",
    "Do NOT reboot the infected machines, as the encryption keys may still reside in volatile memory (RAM), which is critical for potential forensic recovery.",
    "Check for and sever any active C2 connections or unauthorized remote access tools (like AnyDesk or TeamViewer) dropped by the attackers for persistence."
  ],
  "what_to_avoid": [
    "Do not pay the ransom immediately; engage professional incident response and negotiation firms, as paying does not guarantee a decryptor and funds criminal enterprises.",
    "Avoid wiping the machines until forensic images have been captured; crucial evidence regarding data exfiltration is stored in the system logs."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}