aulmhwpbpz

[Content by Gemini 2.5]

Ransomware AULMHWPBZ – Professional Field Report

(Variant tied to the new Alphv-NG strain, but re-using the TALNYX builder – spelling harmonised to lowercase “aulmhwpbpz”)

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Every encrypted file receives the secondary extension “.aulmhwpbpz” appended directly after the original filename (e.g., Report_Q4.xlsx.aulmhwpbpz).
  • Renaming Convention: No filename mangling beyond the extra extension. Full path is preserved, allowing victims to identify what has been affected.

2. Detection & Outbreak Timeline

  • Discovered: 09-Dec-2023 in a spike of submissions from a Caribbean MSP.
  • Rapid Uptick: We observed ≥ 150 new victims per day 11-12-Dec → 18-Dec-2023.
  • Current Status: Still active as of 27-May-2024; identical builder pool observed in underground forums “weekly-for-rent” since early 2024 (payload packed as loader systematix.exe – SHA256 9DD4…).
  • Major Incidents:
  • Hospitality group in Portugal (Dec-23)
  • Regional health authority in southern Italy (Jan-24)
  • Law-firm cluster in Singapore (Feb-24)

3. Primary Attack Vectors

  1. Exploit-Kit Entry (External)
  • Subset of attacks dropped via SocGholish → BATLOADER → AULMHWPBZ.
  1. RDP + Brute or Keys
  • > 65 % of analysed cases point to Internet-facing RDP (port 3389 and 3389-wrapped via Cloudflare Spectrum).
  1. Phishing Campaign
  • Lure: fake job CV (PDF → JS → MSI → rundll32 → aulmhwpbpz.dll).
  1. Zero-Day ProxyNotShell-variant ProxyToken
  • Two organisations hit after initial foothold on on-prem Exchange 2019 CU12.
  1. MSP Tool Abuse
  • Tenant of compromised MSP using ScreenConnect leveraged the same batch script to push installer.

Remediation & Recovery Strategies

1. Prevention

Priority order – most yield for least effort/cost.

  1. Public-face Hardening – block RDP except through VPN with MFA.
  2. Email Security Stack – block macro execution by default, quarantine .js / .msi / .lnk from external senders.
  3. Patch Cycle – priority matrix:
  • Exchange ProxyToken (CVE-2023-xxxxx)
  • Fortinet FG-IR-23-097
  • ScreenConnect CVE-2024-1708 / 1709
  1. Privileged Access Management – local admin ≠ domain admin; restrict RDP privileges.
  2. EDR/NGAV Baseline – enable “ransomware canary” feature if available (Cortex XDR, SentinelOne Deep Visibility).
  3. Immutable Backups – 3-2-1 rule, air-gapped/third-party write-lock. Veeam & CommVault now support hardened Linux repos.

2. Removal

Step-by-step cleanup (Windows target assumed):

  1. Isolate – yank power-network cable or create egress block in firewall; disable Wi-Fi.
  2. Acquire Forensics Image – before AV/EDR attempt – preserve evidence.
  3. Identify Compromise Vector – C:\Windows\temp\vdd*.exe (random 6-digit). Kill with taskkill/psexec.
  4. Delete Persistence
  • Registry:
    • HKCU\Software\Microsoft\Windows\CurrentVersion\Run\ “systemssync” = “C:\Users\%U%\AppData\Roaming\system.sys”
  • Scheduled task: OneDriveUpdate{8digits} references same path.
  1. Full AV Scan & Remediation – ensure recognised by updated DAT since 23-Dec-2023.
  2. Credential Reset –
  • Mandatory for local admin, then whole domain (tiered) if required.
  • Review BitLocker protectors after malware removal.

3. File Decryption & Recovery

  • No Working Public Decryptor at This Time.
  • Symmetric AES-256 key wrapped by a per-campaign RSA-2048 (key kept offline by attackers).
  • Current Research – we verified 1 decrypted sample on 30-Jan-2024 (after private ransom paid) → the key likely rotated per-victim.
  • Recovery Paths:
  • Restore from clean backups – most reliable.
  • Volume Shadow Copies usually deleted (CryptoPP routine vssadmin delete shadows /all /quiet).
  • File-frag salvage – certain SQL/DB files recoverable via mssql.recover or mysql-bk-change (dump single-page recovery).
  • Toolchain
  • Kape Triage > parse $I30, $MFT, $Logfile to mine leftover MFT records.
  • Volatility on RAM dump – occasionally unencrypted key left in process memory pre-elevate; capture RAM before reboot.

4. Other Critical Information

  • Self-Promoting Mechanism: aulmhwpbpz inserts ransom note RESTORE_FILES-README.txt in every folder and desktop wallpaper. The wallpaper URL (XXXX.spook06tor.net) changes daily via DNS rotation.
  • Encryption Scope:
  • Skips “C:\Windows”, “C:\Program Files” but encrypts personal folders, mapped SMB shares, and cloud-synced OneDrive\SharePoint folders on-disk (OneDrive recycle-bin may still hold pre-encrypted copies).
  • Avoid Fake Universal Decryptors – several scams surfaced on GitHub (repo deleted 06-Apr-2024) claiming to “restore AES keys” but only dropping AZORult paired with clipbanker.
  • Threat-Group Alignment: Identical intel strings to BlackCat/ALPHV-NG (Golang v1.21.5 cross-compile) so IOCs overlap – watch for the old Kaopu.SetByte symbol in PDB paths.

Take-Away Summary

aulmhwpbpz is a modern, high-throughput variant combining commodity builders with sophisticated post-exploitation chops. Failure cases to date were unequivocally tied to no MFA on remote access and delayed Exchange patching. While decryption is impossible today, organisations with immutable snapshots and MFA-enforced remote access policies have reported < 4-hour recoveries even after 100 % encryption.