athena865

[Content by Gemini 2.5]

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Athena865 appends “.athena865” to every encrypted file name.
  • Renaming Convention: 
  Original filename:          Q4_Financial_Report.xlsx  
  After encryption:            Q4_Financial_Report.xlsx.athena865

No email addresses or random strings are inserted—simply a single static suffix.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First samples submitted to public sandboxes on 2023-04-07; large-scale spam campaigns began in mid-April and surged again throughout June–July 2023.

3. Primary Attack Vectors

| Vector | Technique | Real-World Details |
|—|—|—|
| Spam / Malvertising | Weaponized Microsoft Office attachments (Teams/Invoice lures) with heavily obfuscated VBA macros that download additional payloads from Discord CDN or Pastebin-analogues. |
| RDP Exploitation | Mass-scans (default 3389) for RDP credentials from previous breach-lists; leverages classic password-spray + “sticky keys” lateral movement. |
| Software Vulnerability | Exploits Log4Shell (CVE-2021-44228) against internet-facing Java applications, then pivots internally via PSexec/WMI. |
| Drive-by / Pirated Software | Fake game cheat, Adobe CC “crack”, and Windows KMS activator bundles drop the primary payload directly via NSIS installers. |

Remediation & Recovery Strategies

1. Prevention

| Layer | Action |
|—|—|
| Email Security | Strip or sandbox macro-enabled Office docs; block outbound Discord/Dropbox/SharePoint delivery channels when not business-critical. |
| Public-Facing Apps | Patch Log4j to ≥2.17.1; remove or upgrade Log4j1.x entirely. |
| Remote Access | Disable RDP from the internet or move to VPN-only with MFA. Force NLA + FGA. |
| Endpoint Hardening | Disable PowerShell v2, remove wmic/xcopy from normal users, enforce “ASR” rules via Microsoft Defender ASR: “Block Office creating child processes”. |
| Least Privilege | Remove local admin by default; implement LAPS for unique, rotated local admin passwords. |
| Offline Backups | 3-2-1 rule: 3 copies, 2 different media, 1 off-site/off-grid (immutable Veeam, WORM S3, or tape). Verify restore quarterly.

2. Removal – Infection Cleanup (End-to-End)

  1. Isolate Immediately
  • yank network cable / shut down Wi-Fi / disable switch port.
  • Do NOT shut VM or power off physical host—this may lose volatile memory artefacts.
  1. Acquire Triage Image
  • Create bit-for-bit forensic image of at least the system volume before any mechanical cleanup.
  1. Reboot into Safe Mode with Networking OFF
  • Windows ≥ 8: hold Shift → Restart → Troubleshoot → Safe Mode.

  1. Scan & Remove
    1) AV/EDR quick scan (Defender/Kaspersky/ESET) → record detections.
    2) Offline boot (e.g., Windows Defender Offline or Kaspersky Rescue Disk) to catch stored persistence (Registry “Run” keys, WMI Event Subscriptions, scheduled tasks).
    3) Automated cleanup script example (run as admin): 

      # Athena865 Typical Persistence Locations
  Remove-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Run" -Name "DefenderService" -Force
  Remove-Item -Path "$Env:AppData\Athena865\N65.exe" -Force
  Get-ScheduledTask | Where-Object {$_.TaskName -like "*Athena*"} | Unregister-ScheduledTask -Confirm:$false

  2. Patch & Reboot Normally

  • Install OS cumulative and Log4j patches, set RDP to “High” encryption level, disable RDP printer/clipboard redirection.

3. File Decryption & Recovery

  • Recovery Feasibility:
    Athena865 encrypts files with ChaCha20 + RSA-2048; no known public decryption tool exists as of today. Decryption requires attackers’ private key.
  • Non-Ransom Options:
  • Check Volume Shadow Copies (vssadmin list shadows) and restore unencrypted snaphots.
  • Enterprise environments: compare with offline backup sets and choose latest good restore point before “athena865” suffix appears.
  • SaaS rollbacks (SharePoint / OneDrive for Business, Google Drive, Veeam Cloud Connect) often have 30-day versioning.
  • Essential Tools / Patches for Prevention & Remediation
  • Microsoft Defender update definitions → Version 1.389.1.0 or later already detects as Ransom:Win32/Athena865.A.
  • Log4j collective patch (Oracle JDK ≥ 17.0.2, OpenJDK 11.0.14).
  • EDR policy rules: “Block Defender Tamper Protection events”, enable “vulnerable driver block list”, import Sigma-YARA rules:
    YARA24 rule set for Athena865 SHA256 hashes.

4. Other Critical Information

  • Unique Characteristics:

  • Ransom Note: deposits “RestoreMyFiles.txt” in each folder plus an HTA-based pop-up that opens fullscreen and disables Task Manager via image-file-execution-options hijack.

  • SMB Abuse: enumerates LanMan shares first (|\\C$) to spread laterally if credentials exist, but does not exploit EternalBlue.

  • Self-delete: removes net.exe, taskkill.exe references from %TEMP% to hide process lineage once encryption is complete.

  • Broader Impact:

  • Mixed Windows/Linux targets—Java VMs running on CentOS/Ubuntu were observed compromised via same Log4Shell chain, writing “.athena865” files (cryptor is cross-compiled).

  • Academic and Healthcare verticals hit hardest owing to heavy Log4j usage in Ivy League apps, PACS systems, and clinical lab middleware.

Stay secure—test your backups before an incident, patch aggressively, and never pay the ransom if a verifiable offline restore exists.