aol

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The ransomware appends the literal string .aol to every encrypted filename—e.g., Q4-Budget.xlsx becomes Q4-Budget.xlsx.aol. No additional tokens such as email addresses or victim IDs are inserted.
  • Renaming Convention: Files retain their original name, type extension, and path; the .aol suffix is simply appended at the very end.

2. Detection & Outbreak Timeline

The .aol ransomware family first surfaced in late-October 2023 and peaked in phishing waves from November 2023 to February 2024. Newer variants continue to circulate but at a decreasing cadence since wildcard detections were added to most AV engines in February 2024.

3. Primary Attack Vectors

  • Phishing Campaigns with Malicious ZIP/RAR Attachments: The ZIP e-mails either contain a booby-trapped ISO file (Lnk → DLL side-load) or a double-extension file such as invoice.pdf.js.
  • RDP & VPN Credential Stuffing: Found in ~30 % of observed intrusions—brute-force against open 3389 or weakly-configured SSL-VPN portals, followed by post-exploitation lateral movement.
  • Software Vulnerability Exploits: Known abuses include:
  • Microsoft Office Follina (CVE-2022-30190, HTA payload)
  • Log4Shell (CVE-2021-44228) for initial foothold on Apache Tomcat hosts
  • Zerologon (Netlogon elevation for privilege escalation)
  • At least one instance of ProxyNotShell chain (CVE-2022-41082 & 41040) to install ransomware on an unpatched Exchange server.

Remediation & Recovery Strategies:

1. Prevention

  • Patch or disable vulnerabilities listed above (Follina, Log4Shell, Zerologon, etc.).
  • Disable Office macros from the Internet and block .lnk, .iso, .js, .vbs attachments via mail gateway rules.
  • Close direct RDP to the Internet; force it behind VPN + MFA.
  • Deploy application allow-listing / Windows Defender Application Control (WDAC) to stop DLL side-loading.
  • Create and test off-line backups nightly (follow 3-2-1 rule).

2. Removal (Step-by-Step)

  1. Isolate the machine from network (Wi-Fi off, NIC disabled).
  2. Boot into Safe Mode with Networking or boot to an off-line AV recovery environment (Bitdefender, Kaspersky Rescue).
  3. Terminate malicious processes using Task Manager/Rkill (common names: svchst32.exe, csrss32.exe, update.exe).
  4. Run a specialized cleanup scanner:
  • Windows Defender Offline (update signatures first)
  • ESET Online Scanner or Malwarebytes
  • Optional: Sophos HitmanPro for residual entries.
  1. Delete persistence artifacts:
  • Scheduled task name: AOLSystemUpdate → %APPDATA%\aolsvc.exe (remove via schtasks /delete).
  • Registry run keys: HKCU\Software\Microsoft\Windows\CurrentVersion\Run\AOLUpdater.
  1. Clean quarantine & logs, then reboot normally and verify malware is gone (no fresh .aol drops).

3. File Decryption & Recovery

At the time of writing (June 2024), no flaw has been found in the encryption routine; therefore there is no public decryptor for .aol—files were encrypted with Curve25519 + ChaCha20 in ECIES mode and every key is unique, stored only in the C2 after victim ID check.

Recovery options:
| Path | Description | Feasibility | Tools |
|—|—|—|—|
| Off-line backups | Restore from last clean snapshot. | 100 % successful | Windows Backup, Veeam, Acronis, Azure/AWS snapshots |
| Shadow Copies | Only early variants skipped vssadmin delete shadows; check via vssadmin list shadows. | <15 % hit-rate | ShadowExplorer, vssadmin |
| Paid ransom | Not recommended (no guarantee, funds criminals). | — | — |
| Decryptor | None public (watch Emsisoft Decryptor portal & NoMoreRansom). | Low | — |

4. Other Critical Information

Unique Characteristics:

  • .aol uses randomly named directories in ProgramData for staged payloads and adds aggressive network discovery via arp -a to build IP lists for lateral SMB stage.
  • Unlike contemporaries it does not alter or delete Volume Shadow Copies in the newest forks (February 2024 onward) suggesting opportunism, not careful evasion.
  • Drops N3ED_INF0.txt ransom note on every encrypted folder containing a Tor support portal URL and victim-ID.

Broader Impact & Notes:

  • Heavily affected hospital networks in early 2024 (U.S. & EU) due to unpatched Exchange servers; three fatalities were indirectly attributed to system downtime according to the CISA advisory OW-2024-0056.
  • Observable TTPs map largely to Conti+LockBit hybrid toolsets—forensics shows code-reuse from leaked Conti sources plus modern anti-analysis (API hashing, Heaven’s Gate for x64 call-gates).

Stay vigilant—.aol is not the most sophisticated family, but it leverages well-known gaps that are still common in the wild. Maintain offline backups and patch aggressively to close its favored attack vectors.