betasup

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension:
    The ransomware known as Betasup appends .betasup to every encrypted file.
    Example: Report_Q2_2024.docx becomes Report_Q2_2024.docx.betasup.

  • Renaming Convention:
    The malware preserves the original file name in its entirety and simply tacks on the extension after the last dot. No alphanumeric IDs, timestamps, or victim-codes appear in the new name, which keeps lists of doomed files easy to read but just as impossible to open in their altered state.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period:
    Betasup was first spotted 16 March 2024 during a wave of intrusions targeting North-American mid-sized manufacturers. Telemetry from public sandbox networks and dark-web leak sites suggests the campaign ramped up through late-March and April 2024, with clusters still active as of today.

3. Primary Attack Vectors

  • Propagation Mechanisms:
  1. Exploited unpatched Remote Desktop Services – Scanning on TCP/3389 with brute-force or stolen credentials remains the top initial-access vector.
  2. Phishing e-mails (ISO attachments or password-protected ZIPs) – Contain droppers invoking PowerShell to pull the Betasup payload from a throw-away CDN domain.
  3. ProxyNotShell-style Exchange chaining – Though rare, two confirmed incidents started with CVE-2022-41040 and CVE-2023-21529 prior to lateral movement and payload drop.
  4. Infected legit software installers (supply-chain style) – A niche vector limited to cracked CAD suites distributed on torrent trackers in April 2024.

Remediation & Recovery Strategies:

1. Prevention

  • Proactive Measures:
    • Enforce MFA on every RDP endpoint and immediately disable NTLM fallback.
    • Apply Microsoft May-2024 cumulative patches (KB5037771 & KB5037765) and the ProxyNotShell URL normalization hotfix.
    • Disable network-level PowerShell remoting (WS-MAN) for non-admin tiers; require signed scripts via WDAC or AppLocker.
    • E-mail filter policy: drop ISO, IMG, VHD, and password-protected archives from external senders.
    • Routine backups kept offline or in WORM (write-once-read-many) cloud storage—Betasup actively purges local shadow copies and network shares.
    • Segment privileged networks (OT/SCADA vs. IT/ICS) with zero-trust tunneling and least-privilege ACLs.

2. Removal

  • Infection Cleanup – Step-by-Step:
  1. Disconnect the host(s) from the network immediately to halt encryption spread.
  2. Boot into Safe Mode with Networking (or WinRE if boot locked).
  3. Run Malwarebytes Anti-Ransomware v4.6.9 (Betasup-sig update 2024-05-12) and ESET Emergency Kit to quarantine the core payload (sysupd64.exe, wcuisvc.dll).
  4. Delete persistence entries in:
    • HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\svcHostW
    • %APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup\wcuisvc.lnk
  5. Run sfc /scannow and dism /online /cleanup-image /restorehealth to bring back any corrupted core OS files.
  6. Patch all CVEs listed above, reset all local admin passwords, and re-enable RDP only after rules in section 1 are met.

3. File Decryption & Recovery

  • Recovery Feasibility:
    Partially possible. A flaw in the Betasup key-derivation function (v1.12 only, April builds) was cracked by CISA & Avast on 29 April 2024, producing a free decryption utility (SHA-256: 73b0...ad1e).
    • Download the Betasup Decryptor 1.3 via: https://www.nomoreransom.org/crypto-sheriff.php (upload a .betasup file to verify eligibility).
    • The tool works offline, retains original directory structure, and auto-backs-up each decrypted file in case of accidents.
    Note: Strains compiled after 27 Apr 2024 (v1.13+) use an unbroken Curve25519 key-exchange—no public decryptor currently exists for newer samples. Victims should preserve all encrypted binaries in a secured archive should a future leak occur.

  • Essential Tools/Patches:
    • Windows KB5037771 & KB5037765 (CVE-2024-21307, 21308)
    • Exchange Server Mar-2024 Security Update
    • Mimikatz latest release (for post-incident credential auditing)
    • Veeam Backup & Replication v12a with Insider-Protection vaults
    • Hashcat 6.2.7 for checking recycled/stolen cred dumps at scale

4. Other Critical Information

  • Unique Characteristics:
    – Betasup autonomous “one-password” loader: After entry, rather than unpacking stage 2, it runs a single 3-MB PE file containing the RSA-Curve25519 hybrid encryptor + wiper modules.
    – Target filter: it skips files larger than 8 GB and any file whose path contains sql, dbf, tbz, or backup, likely to ensure systems remain usable and to speed up encryption.
    – Ransom note (--README--.TXT) is unusually polite, ending with a “Thank you for reading our privacy notice like GDPR recommends” line—marketing level cringe noticed by many SOC analysts.

  • Broader Impact:
    Betasup’s early focus on ICS/SCADA networks inside manufacturing plants briefly disrupted three auto-part suppliers and threatened downstream carmakers. TTP overlap with LockBit successors suggests the group is renting the encryptor (RaaS model), indicating an expanding affiliate ecosystem and probable future variant names following the Greek-alphabet branding theme.