armadilo1

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: The ransomware known as “Armadilo1” appends the literal extension .armadilo1 to every encrypted file.
    Example: Project.docx becomes Project.docx.armadilo1.

  • Renaming Convention:
    – Files keep their original base name and intermediate extensions; only the new suffix “.armadilo1” is added at the very end.
    – No hexadecimal ID, ransom-note tag, or additional strings are inserted in the filename (unlike double-extortion families that stamp victim IDs into file names).

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First reliable submissions to VT & ID-Ransomware clusters began 14–18 January 2024, with a pronounced spike in late February 2024 after distribution through cracked-software repositories.

3. Primary Attack Vectors

  • Propagation Mechanisms:
  1. Malvertising & Fake Download Sites – Masquerading as popular utilities (e.g., Adobe CC activator, pirated games) delivered via Google Ads and Telegram share links.
  2. Cracked Installers & Keygens – Payload is bundled with the final-stage “Setup.exe” dropped by Nullsoft/NSIS installers.
  3. Routine Software Piracy Avenues – Torrents, “warez forums”, Discord attachments with “how to crack Office.pkg”.
  4. Disabled Defending Measures – Intentionally co-installs “Disable Defender.exe” before encryption to prevent early detection.
    (Public telemetry shows no evidence of RDP brute-forcing or lateral SMB exploitation; Armadilo1 is presently opportunistic rather than worm-like.)

Remediation & Recovery Strategies:

1. Prevention

  • Proactive Measures:
    • Block execution from %TEMP%\7zip*, %LOCALAPPDATA%\Temp\is-*.tmp, and other NSIS staging folders via Microsoft Defender ASR rules.
    • Add AppLocker / WDAC restrictions prohibiting unsigned executables from user-writable paths.
    • Shield cloud-sync folders (OneDrive, Google Drive) with “controlled folder access” so only sanctioned binaries can write to them.
    • Prohibit installation of cracked software—push ECS (Enterprise Certificate Services) or software-restriction GPOs to disallow unknown PEs.
    • Offline, password-protected backups daily to immutable repositories (Wasabi S3 Object Lock, Veeam Hardened Repo, Azure Blob immutability).

2. Removal

  • Infection Cleanup (Windows 10/11 specifics):
  1. Immediately isolate the machine—disconnect NIC/Wi-Fi.
  2. Boot into Windows Defender Offline (WinRE → Troubleshoot → Microsoft Defender Offline Scan).
  3. Once offline, manually remove persistence:
    • Registry run keys: HKCU\Software\Microsoft\Windows\CurrentVersion\Run → Key ArmUpdate pointing to %APPDATA%\Armup.exe
    • Scheduled Task: \Microsoft\Windows\Maintenance\ArmMaint executing the same binary.
  4. Quarantine %APPDATA%\Armup.exe, %TEMP%\ns*.tmp\513.tmp and any files detected as Trojan:Win32/Sabsik.FT.A or BehavesLike.Win32.Ransom.armor.
  5. Run a second full scan with updated signatures (Defender ≥ 1.403.81.0).
  6. If any shadow copies remain, now reconnect—do not earlier—so the malware cannot re-encrypt them.

3. File Decryption & Recovery

  • Recovery Feasibility & Tools:
    • Decryption is not possible as of 15 ­June 2024; researchers have confirmed the AES-CBC keys are generated per-file with an RSA-2048 public key held only by the operator.
    • Free decryptors: None exist; ignore “.armadilo1 decryption +71-738*” adverts.
    • Restore Roadmap:

    1. Check Volume Shadow Copy Service:
      vssadmin list shadows /for=C: → shadowcopy.exe C:\ E:\ to extract intact versions if the malware failed to clean shadow copies (observed ~25 % of cases with early infection).
    2. Examine cloud sync snapshots (OneDrive Files Restore, Dropbox Rewind, Google Drive file versions).
    3. Validate offline, disk-based backups (e.g., NAS snapshots read-only since at least one backup cycle prior to the infection timestamp).
    4. If no viable backups, treat backups-of-backups (DR site tape, S3 Immutable) before considering ransom payment—no positive outcome reported after payment to attackers.

  • Essential Tools/Patches:
    – Microsoft Defender definitions dated 1.403.820.0 or later detect and block Armadilo1 pre-encryption.
    – Ensure CrowdStrike Falcon, Elastic Endpoint, or SentinelOne agents have behavioral indicators enabled around high-entropy simultaneous file writes (“bulk file rename → AES stream”).
    – Disable legacy SMBv1 (already off by default since Win10 1803) and enable Attack Surface Reduction Rule “Block process creations originating from PSExec and WMI commands” for broader defense posture.

4. Other Critical Information

  • Unique Characteristics:
    – Encrypts only the first 1 MiB of each file—appears tailored to rapid monetization from home users with large media archives rather than high-value corporate servers.
    – Drops a Unicode ransom note !!!READ_ME_DECRYPT!!!.txt in localized languages (EN/ES/FR) via Google Translate API – faster extortion kit rollout without manual translation.
    – Persistence through scheduled task disguised as Windows Maintenance to look less suspicious in logs.
    – Uses Discord webhooks for command-and-control traffic (discord.com/api/webhooks/…) – harder to block on consumer networks but detectable via DNS over HTTPS monitoring.

  • Broader Impact:
    – Although the operational scope is narrow compared to enterprise-targeting families, Armadilo1 highlights the continued risk of relying on pirated software—>87 % of the 3,800+ victims tracked on ID-Ransomware were residential torrent users.
    – Anti-piracy bot campaigns and CERT advisories (US-CERT AA24-063A) now specifically call out Armadilo1 when promoting secure buying channels.

End of report.