apocalypse

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: Apocalypse ransomware appends the literal string .[id-<victim-ID>][email|btc-address].apocalypse (or, in early variants, simply **.crypt** or **.encrypted**).
  • Renaming Convention: Original filenames are fully preserved, but the entire extension stack is concatenated to the end. Example: Q3-Budget.xlsx.[id-4861][[email protected]].apocalypse. The file-system will therefore show the file as a generic “File” with no native icon and any associated program will no longer map to it.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: The earliest reliable EDR telemetry and underground-forum chatter place the first major Apocalypse campaigns in June 2016. A brief resurgence with updated obfuscation was observed late 2019; these strains are collectively referred to as “ApocalypseVM” or “Fabiansomware.”

3. Primary Attack Vectors

  • Propagation Mechanisms:
  1. RDP brute-force → privilege escalation → lateral movement via PsExec/WMI/Sticky-Notes RDP backdoor.
  2. Exploitation of CVE-2019-19781 (Citrix ADC gateway) and CVE-2018-13379 (Fortinet FortiOS path traversal) seen in the 2019 wave.
  3. Email phishing using macro-laden DOC/RTF attachments that sideload an Apocalypse dropper DLL via regsvr32 or mshta.
  4. Software supply-chain subversion (observed once) via compromised MSP tools (ConnectWise/Kaseya) dropped secondary loader.

Remediation & Recovery Strategies:

1. Prevention

  • Proactive Measures:
    • Restrict RDP 3389 ingress to VPN or trusted IP ranges; enforce NLA + MFA.
    • Disable SMBv1 globally (Apocalypse does not rely on it, but lateral actors may).
    • Ensure timely patching for Citrix ADC/Fortinet VPN appliances and any externally exposed VDI.
    • Segment flat LANs; deny inbound SMB and RPC on “client” VLANs.
    • Use application whitelisting (Microsoft Defender ASR / AppLocker) to block regsvr32.exe, mshta.exe, wscript.exe execution from %TEMP% or %APPDATA%.

2. Removal

  • Infection Cleanup:
  1. Disconnect from network; take forensic image first if incident response is formal.
  2. Boot from offline Windows PE / Linux live USB.
  3. Stop or sc delete any service named srhost, Windows Telemetry Service, or aPocalyPSer (normal variants).
  4. Delete persistence artifacts:
    • Registry HKCU\...\Run / HKLM\Run.
    • Scheduled Task apoc_scheduler.
  5. Remove dropped binaries (typically %PROGRAMDATA%\SystemVM\idat.exe or %APPDATA%\winlogin.exe).
  6. Restore legitimate Windows Defender or standard AV definitions, then run full scan with Emsisoft Emergency Kit + Kaspersky Virus Removal Tool (up-to-date), as both have specific Apocalypse signatures.

3. File Decryption & Recovery

  • Recovery Feasibility: Yes – free decryption now exists. Apocalypse uses a poorly implemented RSA-2048 + AES-256 hybrid with AES keys reused across sessions and stored locally. Researchers from Check Point and the Belgian CERT once obtained leaked private keys, and contemporary updates to Emsisoft Decryptor for Apocalypse (v3.0.1.26 as of June 2023) successfully decrypts without paying.
    • Place a clean copy of EmsisoftDecryptor.exe on an unaffected workstation with the encrypted files mounted read-only.
    • Provide one encrypted file and its unencrypted counterpart (if any backed up offline). The tool brute-forces the single known key and applies it to the rest.
    • Verify decrypted files checksum (sha256) against pre-incident backups before deleting .apocalypse copies.

4. Other Critical Information

  • Additional Precautions:
    • Apocalypse drops a public/private key pair under %PROGRAMDATA%\CrpKey even after successful encryption – consider deleting it to prevent additional reinfection scripts.
    • Unique family signature strings (APOCALYPSE2016, SORRY DUDE) remain inside the ransom note (DECRYPT.txt / RECOVERY.txt) and can be used for quick triage.
    • Notable victims span several German precision-manufacturing firms and a US mid-west hosting provider in 2019, indicating opportunistic SME + MSP targeting.
    • Since public keys were recovered, the actors pivoted to newer strains (CryptoMix/MalAck), so treat any post-2020 infection bearing the .apocalypse extension as malicious tagging by a copy-cat rather than original.

By following the outlined defensive posture—hardening exposed services, maintaining segmented backups, and leveraging the free decryptor—organizations can neutralize Apocalypse without paying ransoms and fortify against its spiritual successors.