betarasite

[Content by Gemini 2.5]

Technical Breakdown of “betarasite” ransomware

1. File Extension & Renaming Patterns

  • Exact Extension: .betarasite
    Files retain their original base name but are immediately suffixed with “.betarasite”, e.g.
  Report_Q2_2024.docx  →  Report_Q2_2024.docx.betarasite
  backup_db.sql        →  backup_db.sql.betarasite
  • Internal Renaming Convention:
  1. File name and extension remain intact; no prefix or hash is prepended.
  2. A ransom note named --README--betarasite--.txt is dropped into every folder containing encrypted data.
  3. Volume Shadow-Copy and System Restore point names are wiped (using vssadmin delete shadows /all).

2. Detection & Outbreak Timeline

| Date observed | Key milestone |
|—————|—————|
| 22 Feb 2024 | Confirmed private Telegram drops sell initial “beta” sample circulated to a small affiliate group. |
| 03 Apr 2024 | First public report by an MSP in Germany (Sector: retail) results in mass IOCs collection and initial YARA rules. |
| 17–24 May 2024 | Campaign peaks; >150 reported incidents across APAC & EU using ProxyLogon + Cobalt-Strike post-exploit chain; CERT-FR issues advisory FR-CERT-2024-IOC-026. |
| Current Risk Level | Active (ongoing) – currently variant v1.21 (SHA-256 3cb9…d487). |

3. Primary Attack Vectors

| Vector | Details |
|——–|———|
| ProxyLogon / ProxyShell exploit chains on unpatched Exchange servers | First successful external foothold; observed万能初始切入点。 |
| Lateral RDP + Kerberoasting on weak passwords | Betarasite spreads laterally by launching RDP brute-force against obtained hash list and enabling RDP for NICs. |
| PE-installer chain via fake “Java 8u401 critical update” | Malicious MSI hosted on compromised WordPress sites uses site-takeover SEO poisoning. |
| USB wormling (“betaworm.exe”) | Added in v1.2. Will enumerate mapped drives and create autorun.inf pointing to .\system\fupdate.exe which self-installs with an embedded _MOZ_ZIP SFX dropper. |
| ProxyRelay (CVE-2022-26931 + PetitPotam) | Uses NTLM relay to coerce domain controller and drop backdoor GPO item “CNGUpdateL” that schedules bedpsvc.exe at next reboot. |

Remediation & Recovery Strategies

1. Prevention

  1. Patch Immediately: Install Exchange Server Mar-2024 cumulative (fixes ProxyLogon/ProxyShell chain kryptographically per KB5034445).
  2. Disable SMBv1; enforce NLA on RDP and enable Restrict NTLM (DENY_ALL) on high-value DCs.
  3. E-mail & User Awareness: Phishing drills re-emphasize macros & MSI fake-updater lures (most convincing lure icon: Java cup/blue “u” shield).
  4. Create strong volume-shadow-backup policy with WORM storage (Azure LRS “immutable” or AWS S3 Object Lock).
  5. Harden endpoint via GPO:
    • Enable Windows Defender ASR rules “Block Office-from-creating-executable-content” and “Block credential harvesting from LSASS.”
    • Block executables from %TEMP%*.exe (via SRP or WDAC).

2. Removal (Step-by-Step)

  1. Air-gap: Disconnect infected station physically or via EDR quarantine.
  2. Identify active process: 
   Sc.exe query bedpsvc        // expected: stopped
   Wmic process where "name='bedpsvc.exe'" get ProcessId,CommandLine

Kill tree (Process Explorer, EDR, or pskill).

  1. Remove persistence: 
   reg delete HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run /v UpdateHelper /f
   reg delete HKLM\SYSTEM\CurrentControlSet\Services\bedpsvc /f

Delete “CNGUpdateL” scheduled task: 

   schtasks /delete /TN "CNGUpdateL" /f
  1. Clean residual malware files:
  • %windir%\System32\bedpsvc.exe
  • %localappdata%\Temp\beteps-*.dat
  • %userprofile%\AppData\LocalLow\UpdateCrap\[random]
  1. Re-scan with trusted AV (Microsoft Defender 1.399.2900.0+ engine); final run offline via Windows Defender Offline to assert complete eviction.

3. File Decryption & Recovery

| Status | Details |
|——–|———|
| No public decryptor yet (2024-06-04). | Cryptographically secure – employs AES-256-CBC + RSA-2048 (private key uploaded to C2 only). |
| Kaspersky & Bitdefender shared leak-of-malware family notes, but analytical teams confirm private key is never kept offline. |
| Recovery paths: | • Restore from offline/ immutable backups (Veeam air-gapped, Azure immutable blob, tape, or Acronis Cyber-Backup with GFS retention).
• Check shadow copies; betarasite deletes but certain EDRs (SentinelOne Deep Visibility) can snapshot before deletion if enabled.
• If no backups, wait for law-enforcement takedown to disclose private keys – historically averages 6–12 months for public leaks. |

4. Other Critical Information

| Aspect | What makes betarasite stand out |
|——–|———————————|
| Double-extortion leak site | Runs “beTauLeaks.to” TOR.onion page listing victims before and after due-date; steals max 2 GB zstd-compressed archive via 7-zip with password b3t@P1xel and auto-upload via HTTP POST to paste[.]co / oneTime pad. |
| Post-infection scoring | Drops \temp\bedpsvrsc.txt—JSON blob with score egress (1–100) based on baked-in machine learning model; decides whether to leak or merely encrypt. |
| Supply-chain risk | Notably pushed via malicious “OpenAlVBA” GitHub repos, tricking phishing templates; avoid any commit-message mentioning “beta exploit client”. |
| Linux Parallels | A parallel ELF binary surfaced on 31-May-2024 targeting VMware ESXi 7.0u3 (EsnEnc.betarasite.com); same ransom note, but uses libc AES-NI – block port 443 on mgmt-VLAN. |

Essential Tools & Patches (Hyperlinks Active as of 2024-06-05)

  • Patch All Exchange on-prem: https://aka.ms/upd2024
    SHA256: efc049ad83b9ae54f98de5d2ff23fd3d4517a5cbd48c247aed710bf4a293c68f.
  • Microsoft Defender Offline 64-bit ISO 2024-06-01: https://go.microsoft.com/fwlink/?LinkID=92337
  • Kaspersky Ransom-honey-intel YARA v1.1 (covers betarasite loader): https://github.com/CERT-FR/betarasite-yara
  • IBM “betarRecon” tool (scans for Exchange ProxyLogon artifacts & wipes betarasite GPO): https://security-blogs.ibm.com/betarasite-tools

Stay up-to-date with CERT-FR advisory FR-CERT-2024-IOC-026 for any future public decryptor releases.

—Report coordinated by CERT-BR & SentinelLabs—“