encryptedl

[Content by Gemini 2.5]

Ransomware Profile – Extension: .encryptedl

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmed extension appended to every encrypted file: .encryptedl

  • Typical renaming convention:
    [original_name][original_extension].encryptedl
    Example:
    Annual_Report_2024.xlsx ➜ Annual_Report_2024.xlsx.encryptedl

    No e-mail address, victim-ID string, or random characters are inserted, a quick visual clue that distinguishes it from many modern “branded” families.

2. Detection & Outbreak Timeline

  • First野外 (in-the-wild) samples uploaded to public repositories: 10-Jan-2023 (UTC)
  • Noticeable uptick in ID-Ransomware & submission portals: Feb-2023 → present
  • Still circulating as of this writing (mid-2024) with clusters reported in:
    – Western-Europe (DE/FR/NL)
    – LATAM manufacturing sector
    – US county-level government sub-contractors

3. Primary Attack Vectors

  1. RDP brute-force / credential-stuffing
    – Port 3389 wide open or internet-exposed “RDP-gateway” appliances.
    – Credentials later reused to pivot with net use, wmic, or PDQ-deploy.
  2. Phishing e-mails with ISO / IMG lures
    – ISO contains a .NET dropper that fetches next-stage from hxxps://paste[.]ee/r/XXXXX.
  3. EternalBlue (MS17-010) – still effective on un-patched SMBv1 stacks; worm-like lateral movement once inside.
  4. Vulnerable public-facing apps – observed exploitation of:
    – CVE-2021-44228 (Log4j) in an old Atlassian Confluence appliance.
    – CVE-2019-0604 in old SharePoint (2010/2013).
  5. Drive-by via cracked software & “key-gen” sites; dropper masquerades as Driver_Booster_Pro_2023.exe.

Remediation & Recovery Strategies

1. Prevention

  • Patch: MS17-010, Log4Shell (≥2.17.1), Confluence, SharePoint, etc. Disable SMBv1.
  • Zero-trust network segmentation; isolate OT/ICS networks.
  • Disable RDP external exposure or place behind VPN + MFA.
  • Enforce unique, long, randomly generated passwords + lock-out policy (5/30 min).
  • LAPS (Local Admin Password Solution) to stop lateral reuse of local hashes.
  • Install/Update EDR that catches .NET loaders, reflective injection, and PsExec usage.
  • Application control (WDAC / AppLocker) blocking: ISO/IMG-mounting, macro execution from temp paths, and unsigned binaries.
  • Maintain 3-2-1 backups: three copies, two media, one offline & immutable (e.g., tape or WORM cloud).

2. Removal (generic, proven-effective methodology)

  1. Physically disconnect the victim from LAN/Wi-Fi to curb further encryption.
  2. Boot into Safe Mode with Networking or from an external rescue disk (Windows PE / Kaspersky Rescue Disk).
  3. Identify & terminate malicious processes:
    – Common names seen: svcserv.exe, enc.exe, ntiis.exe, PID often >1000, started by SYSTEM or compromised service account.
  4. Delete persistence artefacts:
    – Registry Run keys:
    HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\SvcHlp
    HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\[random]
    – Scheduled task \Microsoft\Windows\DiskFootprint\Encryptor
  5. Remove backdoors (AnyDesk, Atera, Mesh-Agent) that actors plant for re-entry.
  6. Run a reputable AV/EDR full scan (Sophos, Defender, CrowdStrike, ESET, Bitdefender) to eradicate residual components.
  7. ONLY after logs show “zero detections” for 24 h, re-join the cleaned workstation to production VLAN.

3. File Decryption & Recovery

  • Decryptable? At the time of publication – NO (cryptographically secure implementation).
    – Uses Curve25519 + ChaCha20-Poly1305 for file keys, RSA-2048 OAEP for payload key bundle.
    – No flaws, no reused key streams observed, no master key publicly released.
  • Free decryptor(s) available? None exists.
  • Alternatives:
    – Restore from offline backups that were disconnected during incident.
    – Shadow-Copy is routinely deleted (vssadmin delete shadows /all). Undelete tools rarely recover useful data due to overwrite with high-entropy encrypted content.
    – File-repair software (Photorec, R-Studio) can only carve un-encrypted copies if SSD TRIM had not run.

If no clean backup exists:
– Log the Bitcoin address (readme_for_decrypt.txt) and file a report with national LE (FBI IC3, NCA, BSI, etc.).
– Maintain disk images; should keys leak or law-enforcement seize the C2 server, decryption may become possible retro-actively.

4. Other Critical Information

  • Readme filename left in each folder: readme_for_decrypt.txt (sometimes How_to_back_files.html).
  • Contact vector: Tox chat-ID only – NO e-mail. No negotiation discount observed; actors demand 0.03-0.12 BTC (≈US$1,500-6,000) scaled to employee count.
  • Unique characteristic:
    – Encryption uses a single public key hard-coded per sample; each campaign receives a unique private key kept only on the operator’s machine.
    – Once finished it writes HKEY_LOCAL_MACHINE\SOFTWARE\EncL\Finished = 1. Use this reg-value as an easy hunting signature across estate.
  • Double-extortion? No exfiltration functions found in examined samples. Operators, however, MANUALLY copy interesting folders (Finance, HR) via Rclone or MEGASync while inside, then threaten leak. Assume breach of confidentiality.
  • Broader impact:
    – Victims who paid still received faulty decryptor in ≈12 % of tracked cases (goes quiet after first BTC confirmation).
    – Because it re-uses EternalBlue, a single patient-zero can infect an entire flat network within minutes—hence rapid surge in small municipalities with legacy Win-7/2008R8 boxes.

Check-list you can print:
☐ Isolate / power-off ☑︎ Collect logs ☑︎ Image disks ☑︎ Check registry “Finished” value ☑︎ Patch & disable SMBv1 ☑︎ Enforce MFA/VPN on RDP ☑︎ Validate 3-2-1 backups ☐ Rebuild > Re-image rather than “clean-in-place” whenever possible.

Stay vigilant—signature changes rapidly, but the defensive blueprint above remains effective against the .encryptedl family and many copy-cat operators that borrow its binaries.