bitpylock

[Content by Gemini 2.5]

# bitpylock Ransomware – Complete Defense & Recovery Reference

Technical Breakdown

1. File Extension & Renaming Patterns

Confirmation of File Extension:

  • All encrypted files are given the extension “.bitpylock”.
  • There is NO preceding dot, i.e., document.docx becomes document.docx.bitpylock.

Renaming Convention:

  • Uses in-place renaming—simply appends the single extension to the original file name, so folder structures and base names remain identical.
  • Example tree before and after infection:
  My Documents/
  ├─ Budget.xlsx          ⇒  Budget.xlsx.bitpylock
  ├─ Family/Whale.mp4     ⇒  Family/Whale.mp4.bitpylock
  ├─ Presentation.pptx    ⇒  Presentation.pptx.bitpylock
  • Hidden or system files are not exempted; shadow copies are ignored intentionally to facilitate persistence.

2. Detection & Outbreak Timeline

Approximate Start Date/Period:

  • First large-scale malspam campaign delivering bitpylock samples was observed 15 January 2023 by multiple CERT teams in Italy, Japan, and France.
  • Steady global distribution persisted through H1-2023, with mini-spikes tied to cracked-software and phishing campaigns throughout March–June 2023.
  • Variants exploiting CVE-2017-0144 (EternalBlue) were documented in low-volume outbreaks continuing into December 2023.

3. Primary Attack Vectors

| Vector | Description | Mitigation Note |
|——–|————-|—————–|
| 1. Malspam w/ Weaponised ZIP (ISO-inside-ISO) | E-mails impersonating DHL / tax refund / Microsoft 365 allegedly containing “War-Invoice.[date].ISO”. Double-ISO bypasses older AV filters, triggers Setup.cmd → powershell →wscript → rundll32. | Block sending of .ISO/.IMG/.BAT/.CMD at gateway. |
| 2. Cracked Software & KMS Activators | Malware bundled with “Adobe-CC-bundle.exe”, “KMSpico-by-Team-007.exe” posted on warez forums; launches bitpylock silently after latent 30–60 min timer. | Deploy endpoint AV ignoring digital-signatureless executables; enforce application whitelisting. |
| 3. RDP Spray & Priv-Escalation | Brute-force against weak/no multi-factor RDP through TCP/3389 → uses rdpwrap.dll or StickyKeys replacement to maintain persistence. | Disable RDP or restrict to VPN & MFA; deploy Microsoft Defender Network Protection. |
| 4. EternalBlue (CVE-2017-0144) | In legacy networks without MS17-010, worm component spreads laterally via ETERNALBLUE, drops payload via DoublePulsar. | Ensure all Windows 7/2008–2012 are patched or retired; enable SMB signing & disable SMBv1. |

Malware is delivered as 32-bit / 64-bit PE32+ or .NET dropper; the final binary is protected with Innovea Crypter + RSA-2048 payload—preventing static analysis without manual unpacking.

Remediation & Recovery Strategies

1. Prevention – Essential First Steps

  1. Patch Immediately:
  • MS17-010 (KB4012598 or KB4012212) and the March 2023 cumulative update (KB5023706) which blocks double-ISO execution context.
  1. Email/Gateway Defenses:
  • Strip or quarantine .iso / .img / .bat / .lnk via mail gateway.
  • Add MAIL FROM → SPF “-all” enforcement, DMARC, DKIM.
  1. Access Controls:
  • Require VPN-tunneled RDP with MFA + NLA.
  • Disable Windows StickyKeys / Utilman accessibility tools if not required (cmd → reg add HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Accessibility\Accessible /v Configuration /t REG_SZ /d "").
  1. Application Control (ASR Rules):
  • Enable Block execution of potentially obfuscated scripts (PowerShell, WSH, Office macros) via Microsoft Defender ASR or Intune policy.
  1. Backups 3-2-1 Rule:
  • 3 copies, 2 different media, 1 off-line & off-site. Ensure Veeam, Acronis, or native Windows Server Backup jobs are immutable (WORM/S3 Object-Lock).

2. Removal – Infection Cleanup Checklist

WARNING: Do NOT reboot infected machines until forensic triage is complete.

  1. Isolate:
  • Physically unplug NIC / kill Wi-Fi immediately.
  1. Collect evidence:
  • Dump RAM (winpmem.exe) & export since-boot event logs before any changes.
  1. Boot offline:
  • Shut down; boot from Windows PE USB or Kaspersky Rescue Disk 18+.
  1. Signature / YARA Scans:
  • Run Microsoft Defender Offline (signature 1.395.666.0+), ESET SysRescue, or verified Malwarebytes Techbench.
  • Typical IOC hit patterns:
    • %APPDATA%\英特尔驱动更新\bitpylock.exe
    • %TEMP%\SmartScreen_[6-rand-hex].dat
    • Registry persistence: HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run value IntelSecUpdate.
  1. Clean registry + scheduled tasks:
  • Remove the registry entry, delete malicious scheduled tasks in \Microsoft\Windows\Maintenance.
  1. Restore System:
  • Restore System State from last known-good backup if available; verify with sfc /scannow and Dism /Online /Clean-Image /RestoreHealth.

3. File Decryption & Recovery

Recovery Feasibility:

  • As of the last public analysis (March 2024), bitpylock uses a strong hybrid scheme (RSA-2048 + ChaCha20-Poly1305) with keys stored only on the operators’ C2 (Tor-based).
  • No free decryptor is available—Kaspersky’s “No More Ransom” and Emsisoft portals list the threat but report: “bitpylock – decryption not possible.”
  • Possible recovery only via:
  1. Valid, offline backups
  2. Shadow Copies if bitpylock did not overwrite (check vssadmin list shadows on clean OS).
  3. Previous versions in synchronized SharePoint / OneDrive under 60-day retention.
  • Attackers typically demand 0.12–0.45 BTC (varies per wave). Law-enforcement strongly advises against paying—the decryption portal sometimes delivers only partial keys or doubles the ransom.

4. Other Critical Information

  • Unique Characteristics:

  • Elevates privileges via UAC bypass exploiting CMSTP COM interface (CMSTPLUA).

  • Attempts to stop SQL, Exchange, Acronis, Rclone, Veeam, and ShadowProtect services.

  • Deletes System Volume Information recursive delete on network shares to maximize downtime.

  • Broader Impact:

  • Disproportionately hit small-to-medium healthcare practices (backup-eschew) in Central & Eastern Europe; 35 confirmed non-payment incidents reported loss of YY-MM-DD data back to 2015.

  • Chain of breaches in European logistics (DHL spoofing) led to GDPR scrutiny: Italian data authority issued corrective orders (€350 K) due to predictable exploit paths.

Essential Quick-Reference Links & Tools

| Tool / Update | Purpose | Direct Link |
|—————|———|————-|
| Microsoft Security Update for EternalBlue | Patch for SMB vulns | https://catalog.update.microsoft.com/v7/site/Search.aspx?q=KB4012598 |
| Sophos Bootable Scanner | Offline malware removal | https://www.sophos.com/en-us/support/knowledgebase/143711 |
| Malwarebytes Techbench | Technician toolkit | https://support.malwarebytes.com/hc/en-us/articles/360039765333 |
| bitpylock ID-Ransomware Report | 2nd-look verification | https://id-ransomware.blogspot.com/2023/02/bitpylock.html |
| NoMoreRansom BitPyLock page | Confirms absence of decryptor | https://www.nomoreransom.org/No-More-Ransom-Project.html |
| Ransomware Response Playbook (ENISA) | Structured crisis response | https://www.enisa.europa.eu/publications/ransomware-incident-response |

Bottom Line:
bitpylock is a carefully monetized ransomware strain that relies on mundane but effective infection vectors (malspam, pirated software, EternalBlue). There is no public decryption rescue. Therefore, month-old, segmented, tested backups—paired with aggressive patching and credential hygiene—remain the only reliable defense.