bopador

[Content by Gemini 2.5]

RANSOMWARE RESOURCE – BOPADOR (.bopador)

Technical Breakdown

1. File Extension & Renaming Patterns

• Confirmation of File Extension: .bopador (lower-case, placed as a secondary extension, not replacing the original).
• Renaming Convention:
[original_filename].[original_ext].id-[random 8-chars].[attacker_email].bopador
Example: Sales_2024.xlsx.id-1A2B3C4D.[[email protected]].bopador

Files are NOT renamed in system-critical folders (e.g., C:\Windows) to maintain OS stability and give the illusion that the machine still works, increasing the chance the ransom gets paid quickly.

2. Detection & Outbreak Timeline

• Approximate Start Date / Period: 28 January 2024 – active cluster first uploaded to ID-Ransomware. Peak campaigns observed in late February–March 2024. Still circulating as of today (variant of the Djvu/STOP ransomware family, wave #287).

3. Primary Attack Vectors

Bopador uses the same distribution channels as recent Djvu strains:

| Vector | Utilization Details |
|—|—|
| Software-cracking sites & “keygens” | Disguised as Adobe, Office, or game cracks distributed via torrents and rogue forums. |
| Malvertising | Fake browser-update pop-ups from parked/abused ad networks. |
| Exploit kits (RIG, Fallout) | Secondary payload when victims already have vulnerable browser plugins. |
| RDP brute-force | Lightweight credential-stuffing against externally exposed 3389/tcp when cracking distribution slows down. |

## Remediation & Recovery Strategies

1. Prevention

• Patch early & block legacy protocols: Disable SMBv1, enforce network-level authentication (NLA) for RDP, and apply the most recent Windows cumulative security updates.
• Control zero-cost installs: Block EXE files from %TEMP%, AppData\Local\ and %USERPROFILE%\Downloads via AppLocker/Bit9 policy.
• Endpoint detection: Deploy reputable EDR/NGAV that uses behavioral engines (CrowdStrike Falcon, Microsoft Defender for Endpoint, SentinelOne).
• Principle of least access: Remove local admin rights from everyday users; maintain separate admin accounts for higher-privilege tasks.

2. Removal – Step-by-Step

  1. Isolate – Immediately unplug network cable / disable Wi-Fi & VPN.
  2. Identify – Boot into Windows Safe-Mode (Networking OFF) and run a scan with ESET Online Scanner or Malwarebytes (threat name: Ransom.Stop)` – signatures include Trojan.Ransom.Stop, Win32/Filecoder.STOP, etc.
  3. Kill persistence – Remove scheduled task called Time Trigger Task, registry Run key SysHelper, and files in %AppData%\[random chars]\.
  4. Verify removal – Reboot into normal mode; confirm no new .bopador files appear when you create a test document.

3. File Decryption & Recovery

• Recovery Feasibility: Partial & conditional.
• Djvu/STOP often uses offline keys only until February 2024; after that most samples use online keys locked to each victim.
• Check whether your variant used an offline key by opening C:\SystemID\PersonalID.txt or look for t1 in ID strings inside the ransom note.
• Tool: Emsisoft Stop/Djvu Decryptor 2.0.1.0 – if an offline key match exists, decryption is instantaneous.
• No match? – Restoration must be done via backups or data-recovery software (PhotoRec, Shadow Explorer, Recuva). Volume Shadow Copies are wiped by vssadmin delete shadows early, but early snapshots on Veeam/Windows Server may survive external drives.

Backup note: The malware actively terminates processes based on filename – e.g., wbadmin, sql, oracle, veeam – but has weak blacklist logic; network-attached drives (Linux NAS) or immutable cloud backups (S3-object-lock, Azure immutable blobs) are usually safe.

4. Other Critical Information

• Ransom note (_readme.txt / ReadMe.txt) advertises two e-mails (currently: [email protected], [email protected]) and demands $980/$490 payable in Bitcoin to 1JA1z6bNhW5dsFq3sf6nJgCCjNQKhVrQJx**.
• *Unusual anti-analysis techniques*:
• Checks mouse movement > 5000 ms interval; if none → sandbox, exit.
• Payload is hidden in JPEG comment sections to reduce entropy for static AV scoring.
• *Broader Impact* (Feb→April 2024): Over 700 public submissions to ID-Ransomware; small businesses & “prosumer” torrent users have suffered the heaviest losses due to personal NAS backups being externally exposed via SMB/NFS shares.

Key Take-away: Bopador is just the current clothing of the STOP/Djvu criminal syndicate – robust software-restriction policies and offline, immutable backups neutralize nearly every trick used by this family.