{
  "family": "vbclone",
  "sample_count": 601,
  "category": "trojan_generic",
  "description": "Worm:Win32/VBClone is a massive, generic classification for a vast family of worms and trojans compiled using Microsoft Visual Basic (VB), known for their rapid propagation via removable media.<br><br><b>Understanding VBClone</b><br>To an end-user, a VBClone infection is typically characterized by erratic USB drive behavior, missing files, and severe system sluggishness. For security analysts, VBClone represents a classic, noisy threat. Because they are compiled in Visual Basic, these worms are often large, easy to decompile, and relatively simple in their execution. However, their sheer volume and aggressive USB propagation make them a persistent nuisance in enterprise environments.<br><br><b>Execution and Evasion Strategies</b><br>VBClone worms primarily spread by copying themselves to all connected USB flash drives and external hard disks, utilizing the <code>autorun.inf</code> mechanism to automatically execute when the drive is inserted into a new machine. Once on a host, they often hide legitimate user folders and replace them with malicious executables bearing the folder icon. They establish persistence by copying themselves into the <code>%SystemRoot%</code> directory and heavily modifying the Registry Run keys. They frequently disable Task Manager and Registry Editor to hinder manual removal.<br><br><b>Indicators of Compromise & Impact</b><br>Incident responders should look for the presence of highly suspicious, randomly named <code>.exe</code> or <code>.vbs</code> files on the root of USB drives, alongside anomalous <code>autorun.inf</code> files. EDR platforms frequently flag VBClone for its unauthorized modifications to <code>HKCU\\Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\System</code> (specifically disabling Task Manager). The impact is widespread nuisance, potential data loss (via hidden files), and the establishment of a backdoor for further malware downloads.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1564.001",
    "T1562.001",
    "T1036.005",
    "T1091",
    "T1547.001"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1091",
      "name": "Replication Through Removable Media",
      "tactic": "Lateral Movement"
    },
    {
      "id": "T1564.001",
      "name": "Hide Artifacts: Hidden Files and Directories",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1562.001",
      "name": "Impair Defenses: Disable or Modify Tools",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1547.001",
      "name": "Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder",
      "tactic": "Persistence"
    },
    {
      "id": "T1036.005",
      "name": "Masquerading: Match Legitimate Name or Location",
      "tactic": "Defense Evasion"
    }
  ],
  "containment_steps": [
    "Disable the Windows 'AutoRun' and 'AutoPlay' features via Group Policy across the entire domain to halt the worm's primary propagation method.",
    "Confiscate and forensically wipe any USB drives or removable media that were connected to the infected endpoint.",
    "Use EDR or command-line tools to forcefully unhide the legitimate directories on infected USB drives and delete the malicious executables.",
    "Isolate the endpoint and utilize a reputable AV scanner to remove the VBClone persistence keys and restore Task Manager functionality."
  ],
  "what_to_avoid": [
    "Do not insert a potentially infected USB drive into a clean analysis machine unless AutoRun is strictly disabled and the machine is sandboxed.",
    "Avoid manually clicking on 'folders' on an infected USB drive; ensure file extensions are visible, as they are likely the worm executable."
  ],
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}