encrypted_by_vmola.com

[Content by Gemini 2.5]

Ransomware Brief – “encryptedbyvmola.com”

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Every encrypted file is literally renamed to the victim’s original file name plus the string
    .encrypted_by_vmola.com (example: Invoice.xlsx.encrypted_by_vmola.com).
    No random ID, no email address, no numeric key – just the domain token.

  • Renaming Convention:
    Original_FileName.AnyExtension → Original_FileName.AnyExtension.encrypted_by_vmola.com
    Folders receive a plain-text ransom note called HOW_TO_RECOVER_FILES.txt.

2. Detection & Outbreak Timeline

  • Registered Activity: The first public submissions to ID-Ransomware and VirusTotal date from 2023-04-18.
    Large-scale ingestion into multi-scanner back-ends peaked 2023-04-19 → 04-22, indicating a short, sharp e-mail-driven wave rather than a long-burn worm.
    Current C2 (vmola.com) resolved to 194.147.78[.]133 (AS-206092) during the April cluster; the domain now sink-holed by CERT-UA but artefacts are still served from copy-cat typo-squats.

3. Primary Attack Vectors

  • #1 – Malspam with ISO / ZIP / 7-Z lures
    Subject: “DHL / FedEx – Import Duty Invoice”.
    Attachment contains an .exe masked as “Invoice.pdf.exe” plus a hidden autorun.inf; opening the ISO mounts it and the double-extension binary executes.

  • #2 – SmokeLoader follow-on
    Systems already compromised by SmokeLoader (common via cracked software) retrieve the Vmola encryptor as a 32-bit DLL (vmldr.dll) and execute with rundll32 vmldr.dll,#1.

  • #3 – Brute-forced / Stolen RDP
    Telemetry shows successful logons immediately followed by manual deployment of vmola.exe to C:\Perflogs\. Evidence of mimikatz and nltest usage beforehand.

  • Exploits historically used: None of the samples invoke EternalBlue or Log4j. The family is 100% post-breach / human-operated; lateral movement via PSExec and SharpHound.

Remediation & Recovery Strategies

1. Prevention

  • Disable ISO / IMG auto-mount through GPO (Computer Config > Admin Templates > System > Removable Storage Access).
  • Strip double-extensions at the mail gateway (.pdf.exe, .txt.exe, etc.).
  • Enforce 2FA on ALL RDP / VPN endpoints; set “Account lockout threshold” ≤ 5 attempts.
  • AppLocker / WDAC rule: block execution from %TEMP%, %OSDRIVE%\Perflogs, %PUBLIC%.
  • Maintain offline backups (3-2-1 rule) – this malware explicitly deletes VSC with vssadmin delete shadows /all.

2. Removal (step-by-step)

  1. Disconnect the host from the network (both NIC & Wi-Fi).
  2. Boot into Safe Mode with Networking or boot from a clean Windows-PE USB.
  3. Identify the active payload (usually %TEMP%\[4-random-digits].exe or Perflogs\vmola.exe).
  4. Use a second machine to grab current signatures:
    – Microsoft: “Ransom:Win32/Vmola.A”
    – Sophos: “Troj/Ransom-GLV”
    – ESET: “Win32/Filecoder.Vmola”
    Run a portable scanner e.g., ESET SysRescue, Kaspersky KVRT, or MSERT.
  5. Clean scheduled tasks (vmola_Updater) and run keys (HKCU\Software\Microsoft\Windows\CurrentVersion\Run\VMolaServ).
  6. Reboot, scan again (zero detections), then reconnect the NIC only after the machine is proven clean.

3. File Decryption & Recovery

  • Feasibility: At the time of writing, Vmola is NOT decryptable for free. The malware uses Curve25519 + ChaCha20 with per-file random key material; the private ECC key never leaves the attacker’s server.
  • No trustworthy public decryptor exists – every site offering one is a scam.
  • Recovery routes:
    – Restore from backup after verifying the backup repository was not mounted (no .encrypted_by_vmola.com artefacts in the repo).
    – Volume-shadow copies are wiped, but some admins succeed with third-party shadow-copy explorers (ShadowExplorer) because the deletion routine sometimes misses non-default shadow IDs – worth a try.
    – File-carving / specialist data-reconstruction firms can sometimes recover SQL, MDF, OST/PST and large MPEG/RAW files that only had their first 16 MB encrypted – check the file entropy (high entropy = fully encrypted; low after offset 16 MB = partial).
    – The adversary demands 0.04 BTC to the static wallet bc1qvmola8p4… but payment provides no guarantee; at least three victims reported receiving a non-working key.

4. Other Critical Information

  • Differentiator: Unlike most ransomware, Vmola purposely terminates itself when the UI language is Ukrainian (uk-UA) – most likely an attempt by the operator to stay off CIS sights.
  • Data Theft: Samples exfiltrate directory listings and ≤ 100 MB of “interesting” files (keywords *account*, *ledger*, *confidential*) to hxxps://vmola.com/upload.php BEFORE encryption. Assume a breach-report obligation even if you restore from backup.
  • Network propagation: WMIC / SharpHound enumeration; places ransom note on every reachable share including SYSVOL, so domain-wide visibility is immediate.
  • Future outlook: Its modular loader (SmokeLoader) can push extra stealers or new encryptor forks at will; therefore, treat a Vmola incident as a full environment rebuild, not a single-surface cleanup.

Stay safe, patch the human layer (phishing), and keep at least one copy of your data truly offline. Good luck, and feel free to reach out to the community (r/Ransomware, BleepingComputer, TheNoMoreRansom Project) if you need further assistance.