{
  "family": "vbcryptor",
  "sample_count": 3,
  "category": "ransomware",
  "description": "Ransomware:Win32/Vbcryptor is a broad detection name applied to various strains of ransomware, file encoders, and malicious crypters that are compiled using Microsoft Visual Basic (VB) or Visual Basic .NET (VB.NET). Because VB executables are often heavily dependent on the .NET framework and are relatively easy to decompile, malware authors use 'Vbcryptor' wrapper tools to heavily obfuscate their actual payloads, making static analysis extremely difficult.<br><br><b>Understanding Vbcryptor (Visual Basic Crypters)</b><br>To an end-user, an encounter with Vbcryptor usually ends in tragedy: personal files are suddenly appended with strange extensions (like `.locked` or `.crypto`), and a ransom note demands cryptocurrency to restore access. For a malware analyst, encountering a Vbcryptor file means the first step is unpacking. The outer VB layer is rarely the actual ransomware; instead, it is a highly obfuscated 'packer' or 'crypter' designed solely to evade antivirus (`T1027.002`). The true payload (which could be anything from a banking trojan to a well-known ransomware family like Locky or Cerber) is hidden inside, encrypted.<br><br><b>Execution and Unpacking Mechanics</b><br>Vbcryptor variants are distributed via phishing (`T1566.001`), drive-by downloads, or RDP brute-forcing. Upon execution (`T1204.002`), the VB executable loads into memory. It then executes a decryption routine to unpack its hidden payload directly into a hollowed-out process (Process Hollowing - `T1055.012`) like `svchost.exe` or `vbc.exe`. By running the payload exclusively in memory, the malware avoids dropping the true ransomware binary to the disk, bypassing many legacy, signature-based AV scanners. Once the hidden ransomware executes, it begins iterating through local and network drives (`T1083`), encrypting user files (`T1486`).<br><br><b>Indicators of Compromise & Impact</b><br>The impact is catastrophic data loss or severe operational downtime. Host-based IoCs include anomalous child processes spawning from generic Windows executables, mass file modifications (`T1486`), and the dropping of ransom notes (e.g., `DECRYPT_FILES.txt`). Network IoCs may include the payload attempting to communicate with Tor gateways or known C2 infrastructure.",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Vbcryptor and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Vbcryptor 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 Vbcryptor establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Vbcryptor 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 Vbcryptor compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Vbcryptor 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 Vbcryptor employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Vbcryptor 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 Vbcryptor, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for Vbcryptor 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": [
    "T1055.012",
    "T1486",
    "T1027.002",
    "T1083"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-06-09",
  "mitre_attack_detail": [
    {
      "id": "T1486",
      "name": "Data Encrypted for Impact (Ransomware payload)",
      "tactic": "Impact"
    },
    {
      "id": "T1027.002",
      "name": "Obfuscated Files or Information: Software Packing (VB Crypters)",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1055.012",
      "name": "Process Injection: Process Hollowing",
      "tactic": "Defense Evasion"
    },
    {
      "id": "T1083",
      "name": "File and Directory Discovery",
      "tactic": "Discovery"
    }
  ],
  "containment_steps": [
    "Immediately disconnect the infected endpoint from the network (unplug ethernet, disable Wi-Fi) to stop the ransomware from encrypting shared network drives.",
    "Do not immediately reboot the machine; if the ransomware is currently executing, a reboot might destroy the encryption keys temporarily held in RAM.",
    "Capture a full memory dump; analysts can often extract the unpacked payload and sometimes the encryption keys directly from the hollowed process.",
    "Restore affected files from an offline, verified backup solution."
  ],
  "what_to_avoid": [
    "Do not pay the ransom; paying funds criminal organizations and there is no guarantee the decryptor provided will actually work.",
    "Avoid relying on static AV scans of the original Vbcryptor file; the outer VB shell is often highly polymorphic and changes its hash constantly."
  ],
  "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"
  ]
}