agelocker

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • File Extension: .agelocker
  • Renaming Convention:
    Files are renamed to {original_name}.{original extension}.agelocker.
    Example: Invoice.xlsx becomes Invoice.xlsx.agelocker.
    No new base name, prefix, or ransom note is embedded in the file name itself.

2. Detection & Outbreak Timeline

  • First Public Observations: June 2020 (first cross-checked samples submitted to ID-Ransomware and VirusTotal).
  • Peak Activity Window: July – October 2020; sporadic campaigns resurfaced in May 2021, Q1-2023 and most recently late 2024, always tied to small-time crews rather than large RaaS ecosystems.
  • Current Status (2024): Smaller-scale but still circulating—often bundled as a second-stage payload in double-extortion attacks.

3. Primary Attack Vectors

  • Exploitation of Unpatched Servers
    • Microsoft Exchange ProxyLogon (CVE-2021-26855/27065), ProxyShell (CVE-2021-34473/34523/23731).
  • Credential Stuffing & RDP
    • Brute-forced or previously-stolen RDP credentials; once lateral movement begins, agelocker is dropped via PsExec/WMI.
  • Malspam Campaigns
    • ZIP attachments that chain another loader (Vidar, Dridex) which finally executes agelocker.exe. Lure documents abuse template injection or CVE-2017-11882 (Equation Editor).
  • Living-off-the-Land Utilities
    • Uses legitimate Windows cipher.exe /w to overwrite free space after encryption—helping attackers avoid detection by disk-imaging utilities.

Remediation & Recovery Strategies:

1. Prevention

  • Apply ALL Exchange patches to at least March 2023 Security baseline.
  • Block RDP (TCP/3389, UDP/3389) at the perimeter; require VPN + MFA for any remote access.
  • Enforcestrong password & lockout policies plus mMonitor for breached credential dumps.
  • Macro & script execution controls: disable Office macro execution from the internet; add ASR rules to block credential dumping (WinDefender Exploit Guard).
  • Enable Windows Credential Guard & LAPS; restrict lateral PsExec usage via Applocker.
  • Daily, air-gapped backups with an offline “break-glass” account.

2. Removal

  1. Isolate Network
    – Physically disconnect or firewall-isolate the affected subnet.
  2. Capture Memory & Disk Images if forensics required (before reboot).
  3. Kill Process Tree
    – Identify the main agelocker.exe (randomly-named) and terminate via Task Manager / Pskill.
  4. Disable Malicious Scheduled Task
    – schtasks /delete /tn agelocker_run (custom task created to respawn on reboot).
  5. Start Clean from Known-Good Media
    – Boot WinPE or Safe Mode; run reputable AV/EDR full scan (HitmanPro.Alert, Malwarebytes, SentinelOne).
  6. Change Local & Domain Credentials before reconnecting.

3. File Decryption & Recovery

  • Decryption Feasibility / Tools:
    • No known public decrypter exists—victims after 2022 typically cite unique RSA-2048 keys per victim.
    • Older “testing builds” from July 2020 used a hard-coded [redacted] private key and early claims exist of recovery via Emsisoft_AgeLocker_Decryptor_v1.0.0.0—but this tool only matched Sample_SHA-256: f659...c13a (now deprecated). If you find files encrypted in only this exact time-window, test the tool offline.
  • If offline backups exist, restore immediately after ensuring the network is clean.
  • Shadow-copy treatment differs: most post-June 2022 samples execute vssadmin delete shadows /all /quiet, leaving no shadow copies for recovery.

4. Other Critical Information

  • Unique Characteristics:
    • Timestamp-based Ransom Note Name: README_TO_RESTORE_[Y-M-D_H-M-S].txt instead of fixed READ_ME.html.
    • Chained Encryption: Salsa20 for bulk file data, RSA-2048 for key headers. Uses open-source lib “CryptoPP”.
    • No list of excluded processes— intentionally targets SQL Server, Exchange, IIS to maximize downtime.
  • Wider Impact:
    • Hitting primarily small to mid-tier healthcare and manufacturing entities that delayed Exchange patching; long outage windows (avg. 19 days) according to 2023 incident-response blogs.
    • Because it is not sold via major RaaS portals, negotiation is ad-hoc; payment addresses occasionally recycled across unrelated campaigns, indicating semi-private affiliate program.

Patch, Backup, Block RDP—then test restores.