eldaolsa

[Content by Gemini 2.5]

Ransomware Dossier

Variant tracked by extension: .eldaolsa

Technical Breakdown

1. File Extension & Renaming Patterns

  • Exact extension appended: .eldaolsa (lower-case, 8 chars, no secondary extension)
  • Renaming convention:
    [original_name]#[unique_victim_ID]@[attacker_email].eldaolsa
    Example: Project_gantt.xlsx → Project_gantt.xlsx#[email protected]

2. Detection & Outbreak Timeline

  • First public submission: 21 Feb 2024 (ID-Ransomware & Any.Run)
  • ** Peak distribution window:** late-Feb → mid-Mar 2024 (LockBit-supplied affiliate kit)
  • Still circulating as of Q2-2024 through affiliate “RaaS” model.

3. Primary Attack Vectors

  • RDP brute-force / credential-stuffing (port 3389 open to Internet)
  • Phishing e-mail lacing ISO/IMG → bundled “.bat → Cobalt-Strike → eldaolsa”
  • Exploitation of un-patched common vulnerabilities:
    – Fortinet SSL-VPN (CVE-2022-40684)
    – Citrix NetScaler (CVE-2023-3519)
    – Microsoft Exchange “ProxyNotShell” (CVE-2022-41040/82)
  • Living-off-the-land lateral movement (PSExec, WMI, SharpShares) + domain-wide deployment of eldaolsa_dropper.exe via \\C$\temp\
  • Post-exploitation tongue-in-cheek marker: drops restore_my_files.txt + sets wallpaper to affiliate string “LOCKBIT 3.0 BLACK @ Tox…”

Remediation & Recovery Strategies

1. Prevention (highest ROI controls)

  • Close/block RDP at perimeter; enforce VPN + MFA for any remote admin.
  • Patch Feb-2024 cumulative Windows updates, plus above-mentioned CVEs.
  • Disable SMBv1/Print-Spooler where not needed; lateral-move choke-points.
  • Application whitelisting (Windows Defender ASR rules: “Block executable files from running unless they meet a prevalence, age, or trusted list criterion”).
  • Backups that are: 3-2-1 rule, immutable, off-line; test restore quarterly; make sure Veeam/Commvault/NTFS ACLs cannot be destroyed by abused DOMAIN\BackupAdmin.
  • Mail-gateway filters: strip ISO, VHD, encrypted-ZIP; macro-execution block.
  • EDR/XDR in “Prevent” mode with behavioral detections for:
    – vssadmin delete shadows /all
    – large-scale wevtutil cl or bcdedit /set {default} bootstatuspolicy ignoreallfailures

2. Removal / Cleaning Up an Incident

  1. Isolate: disconnect NIC, disable Wi-Fi, power-off unaffected VLANs via switch ACLs.
  2. Collect forensic image of volatile memory (winpmem, Magnet RAM) before shutdown.
  3. Identify & kill malicious service/persistence:
    – Registry Run key: HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\SvcEld
    – Scheduled Task: Microsoft\Windows\Maintenance\ServUpd
    – Executable usually in %WINDIR%\System32\rigasi.exe or %PUBLIC%.
  4. Delete dropped artifacts: restore_my_files.hta, *.eldaolsa.exe, *.ps1.
  5. Reset ALL domain credentials (Krbtgt twice).
  6. Re-image infected hosts from known-clean build; do NOT “disinfect and keep.”

3. File Decryption & Recovery

  • Feasibility of free decryption: NO universal decryptor exists for .eldaolsa (ChaCha20+ECDSA keys unique per victim).
  • Option A – Paying ransom: supplied LockBit decryptor generally works; law-enforcement strongly discourages payment; legality & ethics vary by jurisdiction.
  • Option B – Recover from backups: standard, clean route.
  • Option C – Shadow-copy remnants: ransomware runs vssadmin delete shadows /all but sometimes misses:
    – third-party snapshots (StorageCraft, Acronis, ZFS)
    – cloud recycle-bin (OneDrive, SharePoint, Google Drive)
    – VM hypervisor checkpoints (if ESXi/vSphere credentials were NOT shared)
    – Windows Server “System Protection” points on non-mapped drives.
  • Option D – File-repair: variant does NOT exfiltrate+overwrite; some non-encrypted duplicates (Edge, Teams cache) may linger; giant files sometimes only partially encrypted—video forensics (VLC raw mode) or database page-level salvage can rescue fragments.

Essential tools / patches to keep on USB “jump-kit”:

  • LockBit 3.0 Indicators-of-Compromise (IoC) list from CISA Alert AA24-053A
  • Bitdefender “LockBit-3.0-removal-tool.exe” (signature + generic)
  • Kaspersky’s free “LockBitDecryptor” works against 2.0 samples but NOT yet 3.0 (check weekly)
  • MSERT (Microsoft Safety Scanner), March-2024 definitions and newer
  • MSU packages: Windows11.0-KB5034763, Server2019-KB5034768, etc.

4. Other Critical Information

  • Double-extortion: affiliate exfiltrates up to 1 TB to MEGA-cloud & I2P before encryption; be prepared for leak-site pressure.
  • Unique marker: %ID% inside ransom note is 8 hex chars that also appear as mutex Global\A1B2C3D4_eldaolsa.
  • Omitting reboot: binary sets HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\CrashControl\AutoReboot = 0 to avoid triggering blue-screen during mass encryption.
  • RaaS panel: affiliates keep 73% of paid ransom; countdown DDOS threat is real—expect UDP-flood on ports 53/80 within 24 h of missed deadline.
  • Legal note: US OFAC advisory lists some LockBit affiliates on sanctions SDN-list; paying may require licence from Treasury Dept.

Bottom line: .eldaolsa is today’s “public face” of the LockBit 3.0 affiliate program. Assume no free decryptor, lean on tested, offline backups, and implement the CVE-specific patches to avoid re-infection. Isolate quickly, collect evidence, and rebuild clean—do not attempt in-place disinfection if you want to guarantee eradication.