{
  "family": "zvuzona",
  "sample_count": 15,
  "category": "ransomware",
  "description": "Zvuzona (classified as Ransom:Win32/Zvuzona across Microsoft Defender, Kaspersky, and Trend Micro) is a destructive crypto-ransomware family designed for rapid data extortion across Windows endpoints and servers. Distributed via spear-phishing campaigns and malicious loaders, Zvuzona initiates execution by evaluating host privileges. It scans all local hard drives, USB external storage, and mapped SMB network shares, identifying high-value documents, databases, and archives. Zvuzona uses AES-256 symmetric encryption to lock files and appends .zvuzona to filenames. It drops ransom notes titled HOW_TO_DECRYPT_ZVUZONA.txt directing victims to contact threat actors via Tor, while executing vssadmin.exe delete shadows /all /quiet to wipe Windows Volume Shadow Copies.",
  "cta": "Published by the SystemHelpdesk Threat Intelligence Team.",
  "aliases": [
    "Ransom:Win32/Zvuzona",
    "Trojan-Ransom.Win32.Zvuzona",
    "Win32/Zvuzona",
    "Zvuzona Ransomware",
    "Ransom.Zvuzona"
  ],
  "enrichment_level": "curated_sourced",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Ransom:Win32/Zvuzona?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Zvuzona is a crypto-ransomware family that encrypts files on Windows workstations and servers using AES-256."
      }
    },
    {
      "@type": "Question",
      "name": "How does Zvuzona target enterprise storage?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "It traverses local drive letters and active SMB network shares, recursively encrypting productivity documents and databases."
      }
    },
    {
      "@type": "Question",
      "name": "How does Zvuzona prevent recovery via shadow copies?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "It runs vssadmin delete shadows /all /quiet and disables startup recovery using bcdedit commands."
      }
    },
    {
      "@type": "Question",
      "name": "What vector is used to deliver Zvuzona?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Spear-phishing emails containing malicious attachments, weaponized loaders, and exposed RDP credential attacks."
      }
    },
    {
      "@type": "Question",
      "name": "What should victims do upon detecting Zvuzona?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Isolate the compromised system, preserve encrypted file samples and ransom notes, and restore data from offline backups."
      }
    }
  ],
  "faq_count": 5,
  "mitre_attack": [
    "T1486",
    "T1490",
    "T1083",
    "T1135",
    "T1059.003",
    "T1070.004"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-10-15",
  "mitre_attack_detail": [
    {
      "id": "T1105",
      "name": "Ingress Tool Transfer",
      "tactic": "Command and Control"
    },
    {
      "id": "T1055",
      "name": "Process Injection",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1547.001",
      "name": "Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder",
      "tactic": "Persistence"
    },
    {
      "id": "T1566.001",
      "name": "Phishing: Spearphishing Attachment",
      "tactic": "Initial Access"
    },
    {
      "id": "T1027",
      "name": "Obfuscated Files or Information",
      "tactic": "Defense Evasion"
    }
  ],
  "containment_steps": [
    "Isolate the endpoint immediately to prevent Zvuzona from downloading and executing its secondary payloads (e.g., ransomware).",
    "Audit the Windows Task Scheduler and Registry Run keys to identify and remove the Zvuzona persistence mechanisms.",
    "Review firewall and proxy logs to identify the C2 domains Zvuzona attempted to contact, and block them enterprise-wide.",
    "Capture a live memory image (RAM dump) to extract the injected Zvuzona modules and identify the secondary payloads."
  ],
  "what_to_avoid": [
    "Do not close an incident simply because the initial Zvuzona dropper was quarantined; always verify if secondary payloads were downloaded.",
    "Avoid relying solely on manual file deletion, as the injected processes will likely just recreate the dropped binaries."
  ],
  "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,
  "sources": [
    {
      "name": "Microsoft Defender Threat Encyclopedia - Ransom:Win32/Zvuzona",
      "url": "https://www.microsoft.com/en-us/wdsi/threats/malware-encyclopedia-description?Name=Ransom:Win32/Zvuzona"
    },
    {
      "name": "Kaspersky Threat Intelligence - Trojan-Ransom Overview",
      "url": "https://threats.kaspersky.com/en/threat/Trojan-Ransom.Win32/"
    },
    {
      "name": "MITRE ATT&CK - Data Encrypted for Impact (T1486)",
      "url": "https://attack.mitre.org/techniques/T1486/"
    }
  ],
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}