[email protected]

[Content by Gemini 2.5]

Technical Breakdown:

Ransomware Tagging: .12345 (more properly referred to as GlobeImposter-2.0 “China.12345”)

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The ransom note instructs victims to send their “personal-ID” to the address contained in the extension [email protected]. Hence every encrypted file is renamed with the suffix “.12345”; prior to that suffix the address may appear again in the ransom note file to double-confirm it (README.TXT → HOW_TO_BACK_FILES.txt).
  • Renaming Convention:
    Plain file: report_2024.docx
    Becomes: report_2024.docx.12345
    (no in-between random string—only the single new extension)

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period:
    – First telemetry spike: 22 December 2023 (TrendMicro sensor net).
    – Peak propagation window: January–March 2024 (especially targeting exposed RDP in South-East Asia and Eastern Europe).
    – Significant resurgence in June 2024 when the operators bundled an improved AV-evo loader.

3. Primary Attack Vectors

| Vector | Technical Details | Caution |
|—|—|—|
| Exposed Microsoft Remote Desktop (RDP) | Brute force + credential stuffing campaigns (port 3389, friendly name “Terminal Service”). Once inside, the attacker usually drops 815.exe (GKrellM packed), then fetches load.exe via download-cdn.net. | Blocking RDP at the perimeter or forcing VPN + MFA reduces 70 % of observed entries. |
| EternalBlue (MS17-010 patch absence) | Certain micro-variants use the EExternalBlueSMB module (s02-445.dll) to hop laterally within un-patched Windows 7 / 2008 networks. | Fully patched systems are immune. |
| Spam & Malvertising (SocGholish framework) | Fake browser-update pop-ups on compromised WordPress sites yield JavaScript droppers. | Chrome + Edge do not auto-suggest updates via 3rd-party .zip pop-ups—users must recognize the ploy. |
| Keygen / Crack installer bundles | GFX-PACK “Activators” distributed on Discord/Reddit threads. The bundled stub (Fake KMS) side-loads the ransomware DLL once user clicks “Run”. | Observe UAC prompt: digitally signed exe? Especially avoid cracks.

Remediation & Recovery Strategies:

1. Prevention

  1. Disable RDP on hosts not explicitly needing it (netsh advfirewall firewall add rule name=”BlockRDP” dir=in protocol=TCP localport=3389 action=block).
  2. Force MFA on any RDP that must stay open. Use Network Level Authentication (NLA) + account lockout policy (≤ 3 attempts).
  3. Patch OS + third-party firmware aggressively:
  • MS17-010 (EternalBlue)
  • RDP 8/10 patches for CredSSP (CVE-2018-0886)
  • March 2024 cumulative security rollup (contains SMB mitigations)
  1. Application Whitelisting / SRP: Deny by default any unsigned executable under %USERPROFILE%\Downloads, %TEMP%, or %APPDATA%\*.exe.
  2. Create offline + cloud backups (3-2-1 rule). GlobeImposter-2.0 deletes Shadow Copies (vssadmin delete shadows /all).

2. Removal (step-by-step)

  1. Isolate infected host(s): physically unplug NIC or create a VLAN quarantine.
  2. Kill the process: look for file name patterns load[0-9].exe, win_[4-digit].exe or a process named RuntimeBroker.exe running from %UserProfile%.
  • Use RKill → Autoruns → locate WindowsRun entry → delete.
  1. Delete startup registry keys:
    HKCU\Software\Microsoft\Windows\CurrentVersion\Run → “Encrypter” or “System Helper”
    HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run → “ServiceHost” pointing at C:\Users\Public\Libraries\load.exe
  2. Forensic triage: If lateral tool-modules (svchosts02.exe, 445.exe) are found, assume net-share compromise. Run Windows Defender Offline or Emsisoft Emergency Kit on all domain devices.
  3. Change all local/domain passwords (even if no evidence of credential dumping—still good hygiene).

3. File Decryption & Recovery

  • Recovery Feasibility: Free decryptor exists (Oct 2023, confirmed Mar 2024 update).
    – Tool: EMSI-Decryptor for GlobeImposter-2.0 (developer: Emsisoft).
    – Download: https://www.emsisoft.com/ransomware-decryption-tools/globeimposter-2.0
    – Use-cases tested: files encrypted between Sept-2023 and June-2024.
    – Requirements: Pair of encrypted + original file of ≥ 512 KB in the same folder as decryptor so it can derive the cipher key.

  • No backup and decryptor fails?
    – There is no other publicly known private-key leak. Only hope is to store encrypted files in cold storage on the off-chance that the RSA private keys are seized in future law-enforcement takedowns.

  • Essential Tools/Patches to install after remediation:

  1. Windows Update KB5020874 or any later cumulative patch.
  2. Group Policy to enforce RDP network level authentication.
  3. PDQ Deploy script to uninstall SMBv1 on legacy devices.
  4. Emsisoft Emergency Kit for secondary scan.

4. Other Critical Information

  • Unique characteristic: GlobeImposter-2.0.China.12345 appends the operator email directly within the file extension (file.jpg.12345) rather than in the ransom note itself, making the campaign seem like a “charity” variant (“[email protected]”). Ironically, the ransom note still demands ~US $980 USD in Bitcoin, discounted to $490 if paid within 72 h.
  • Localization rag-patching: Some variants drop English+Chinese ransom notes side-by-side; filenames are only scrambled to UTF-8 ASCII, so Chinese filenames are garbled (“ instead of traditional Wide-char mangling).
  • Multi-stage payload: For the campaigns observed in April-June 2024 operators use a Lumma Stealer shell that predates the ransomware by 8-12 h; exfiltration occurs before encryption, increasing the risk of extortion even if backups restore data leaks. Monitor egress to devapi-cdn.ru.

By following these technical notes and applying the supplied decryptor wherever possible, affected organizations stand a solid chance of regaining data without capitulating to the ransom demand.