bpws

[Content by Gemini 2.5]

Complete Guide to the BPWS Ransomware

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Every encrypted file receives the “.bpws” extension appended to its original name.
  • Renaming Convention: Files are renamed in the pattern: [original_name.original_ext].bpws (e.g., Quarter-3-budget.xlsx → Quarter-3-budget.xlsx.bpws). The ransomware does not change the base filename itself, which can lessen confusion when assembling shadow-copies or backups.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First widespread detections began mid-November 2023, with a second wave observed in February 2024 that introduced improved privilege-escalation techniques.

3. Primary Attack Vectors

  • Propagation Mechanisms:
  1. Phishing e-mails containing ISO or IMG attachments masquerading as invoices or CVs; if executed, an embedded VBScript downloads the main payload (bpws.exe) from Discord CDN links.
  2. CVE-2023-4966 (Citrix NetScaler ADC & Gateway) exploitation for initial foothold, followed by lateral movement via Cobalt Strike.
  3. Cracked software & game mods on forums and torrent trackers bundled with the loader.
  4. Weak or leaked RDP credentials—dictionary-style brute-force attempts on exposed 3389/TCP ports, then deployment with living-off-the-land PowerShell commands.

Remediation & Recovery Strategies

1. Prevention

  • Proactive Measures:
  • Deploy comprehensive mail filtering to block ISO/IMG attachments or quarantine Office files with embedded macros.
  • Patch Citrix ADC (NetScaler) to the October 2023 hotfix that remediates CVE-2023-4966; disable legacy VPN features if not needed.
  • Enforce SMB signing, disable SMBv1, and segment networks to limit lateral movement.
  • Enforce unique, complex passwords + MFA for all RDP and VPN endpoints; expose only through RD Gateway with MFA.
  • Maintain offline, versioned backups (3-2-1 rule) and set immutable flags to prevent silent deletion.
  • Enable ASR rules and controlled folder access on Windows 10/11 endpoints via Microsoft Defender for Business.

2. Removal

  • Infection Cleanup:
  1. Identify the active process (look for bpws.exe or random-named 8–12-char .exe in %TEMP% and \AppData\Local\). Verify via network connections to C2 (Telegram t[.]me URLs as dead-drop resolver).
  2. Disconnect all affected machines from the network immediately (both wired & Wi-Fi).
  3. Reboot into Safe Mode with Networking or boot a trusted Windows PE from USB to avoid services starting.
  4. Run a reputable boot-level AV scanner (e.g., Malwarebytes’ rootkit removal, Kaspersky Rescue Disk, Bitdefencerescue) and manually delete persistence artefacts:
    • Registry keys: HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\BpwsSync
    • Scheduled task: \Microsoft\Windows\DiskCleanup\Maintenance
    • Hidden folder: %APPDATA%\_bpws
  5. After cleanup, ensure Windows Defender or another EDR engine is updated and full-scan all drives.

3. File Decryption & Recovery

  • Recovery Feasibility:
    – Free decryption is NOT available today. A flaw claimed by researchers in January 2024 was patched by the operators within a week; signatures no longer match the live strain.
    – Your best option is restoring from offline backups or Volume Shadow Copies if they survived (BPWS does delete them, but some users rescued them via TestDisk or Yodot before reboot).
  • Essential Tools/Patches:
  • Use ShadowExplorer to test VSS integrity, or Recuva on drives that have been cleaned but not written to.
  • Ensure servers have October 2023 Microsoft Patch Bundle (KB5028423) – mitigates the PrivEsc chain leveraged by BPWS.
  • For Hyper-V/VMware: enable “snapshot with application-consistent quiescing” and store in immutable S3 / Azure Blob objects to survive tampering.

4. Other Critical Information

  • Unique Characteristics:

  • Wiper-trap behavior: If the ransomware detects non-Russian keyboard layout AND lacks admin privileges, it immediately self-explodes (-wipeclean) using cipher /w on system32 folders, destroying recovery partitions.

  • Decryption twist: “bpws” stands for “BluePrints of WhiteSwan”—a dark-web operator group; they use a future-dated decryptor that fails if the system clock is deliberately set backward.

  • Network discovery script: It echoes the result of arp -a and net view /domain to its C2 to identify AD environments; blue teams should look for unusual UTF-16 in these logs.

  • Broader Impact:

  • First utility company outage reported December 2023 (Australia) after BPWS reached OT networks via default VLAN routing.

  • Interpol coordinated takedown in March 2024 removed the primary VPS command-and-control, yet new binaries still appear daily—evidence of multi-affiliate model.

  • Average ransom demand: 0.7–1.2 BTC (~USD 25–40 k), but double-extortion now threatens to release architectural blueprints (hence the name) if ransom isn’t met under 72 hours.

Bottom line: Right now there is no decryptor for .bpws-encrypted files. Prioritize immediate containment, offline backups, and efficient EDR response to reduce both downtime and reputational damage.