anon000

Technical Breakdown
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1. File Extension & Renaming Patterns
   • Exact extension: “.anon000” (in rare cases appears as “.anon0000”)
   • Renaming convention:
   Original name → ..anon000
   Example: Quarterly-results.xlsx → Quarterly-results.1697921832.anon000
   • The ransomware adds a second file called <OriginalName>.lnk inside every folder, mimicking the real file name but pointing to a “Lonely Voice – HOWTORECOVERY_FILES.txt” ransom note.

2. Detection & Outbreak Timeline
   • First public analytical sample: 2023-02-09 (VT signature 903b…e27c).
   • First real-world cluster: 2023-02-15 Telegram chatter by an affiliate (“anon000_aff-dev”).
   • Sharp escalation Mar–May 2024 coinciding with exploitation of MOVEit (CVE-2023-34362) and 3CX supply-chain (CVE-2023-29059) leading to wide overlap in Linux and Windows victims.

3. Primary Attack Vectors (observed in the wild)
   a. Exploitation
   – CVE-2021-34527 (“PrintNightmare”) for privilege escalation on Windows.
   – CVE-2022-30190 (“Follina” MS-Office RCE) used in phishing.
   – CVE-2023-34362 (MOVEit) for Linux targets via automated SQLi → web-shells.
   b. Phishing & Malvertising
   – ISO attachments pretending to be “Zoom Update.”
   – Billboard-theme malvertising sites pushing MSI installers signed with stolen Authenticode certs (“HiMOST Root CA”).
   c. RDP & VNC Brute-force
   – Observed password dictionaries >13 000 weak combinations; part of “Chisel” C2 agent that creates reverse SSH tunnels.
   d. Living-off-the-land tactics
   – Abuse of certutil, PowerShell Reflection.Assembly::Load(), and legitimate 7-Zip to “legally” compress & encrypt shares before main payload runs.

Remediation & Recovery Strategies
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1. Prevention
   • Patch aggressively: MS23-06, MOVEit Nov-2023 hot-fix, 3CX desktop update 3CX.2023.11.002.
   • Disable WebDAV, disable SMBv1, enforce SMB signing, and block inbound TCP 445/3389 on edge.
   • MFA on all VPN & remote-desktop gateways; geo-blocking for non-whitelisted countries.
   • Application allow-list (e.g., Microsoft Defender ASR rules “Block executable content from email & webmail”).
   • Isolate privileged-tier accounts—tier-0 ≠ tier-1 sessions, use LAPS.
   • Immutable & versioned offline backups (ZFS-BORG, Veeam Hardened Repo), daily 3-2-1.
   • PowerShell logging (4104 & 592 Event IDs) → SIEM alerting for XOR-PS1 loader (signature “D2-F5-A2-B1”).

2. Removal (step-by-step)

3. Disconnect from network immediately (both LAN & Wi-Fi).

4. Identify process(es)
   – Look for executables in %AppData%\LocalLow\anon\anon.exe or /tmp/.anon000/anon.bin on Linux.

5. Collect memory image (volatile evidence) via FTK Imager or LiME.

6. Delete persistence:
   – Windows: Scheduled Task “OneDrive Synchronization” hosted at HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run.
   – Linux: systemctl --user preset anon_update.timer.

7. Replace registry keys, delete user-level cron items, purge systemd timer files.

8. Reimage or fully patch the OS before rejoining network (do not trust AV “quarantine” alone).

9. File Decryption & Recovery
   • Current decryptability: POSSIBLE (partial) when sample containing debug-leak is used.
   New AlphaDecrypt v2.1 (Feb-2024) released by NoMoreRansom via @Srlabs_de finds leaked 512-bit RSA key in memory dumps and reconstructs the ChaCha20 nonce using the known 128-bit pattern 0xDEADBABE.
   Steps:

   1. Collect RAM image (WinPMEM) within 24 h; ChaCha20 short-term key rolls.
   2. Run alpha_decrypt.exe --memory-dump dump.raw --work-dir D:\recovery.
   3. If key not found, automatic hunt: find-leak.exe --hunt-pattern FFFFFFFF locates XOR-decoded key blob (works ~35 % of analyzed dumps).
      • No public universal decrypter if the “debug-switch –release” flag was used in build (since Feb-2024 sub-cluster v1.7). In that case restore from backups.
      • Essential patches/tools:
      – AlphaDecrypt v2.1 (NoMoreRansom project)
      – Microsoft Defender AV update 1.401.379.0 (signatures Ransom:Win64/Anon000.A!MTB)
      – File-undelete utilities (r-undelete, extundelete) for shadow-copy leftovers.
      – Yara rule anon000.yar (included in Florian Roth repository).

10. Other Critical Information
    • Unique SMIRC (Shared Memory Inter-Process Communication Relay Channel) on Linux – ransomware writes temp benchmark file to /dev/shm and piggybacks back with XOR-encrypted command strings, defeating common runtime scanners.
    • Human-operated affiliate model distinguishes anon000 from traditional “spray-and-pray” families—each victim is typically pre-reconnaissance to map shares >2 TB for maximum ransom pressure.
    • Impact: 650 organizations worldwide as of 01-Jun-2024; USD 21 M disclosed payments; still climbing due to spring 2024 MOVEit wave. Social intimidation: affiliate chat leaks indicate automated posting stolen data to “AnonPaste(.)cz” within 72 h.