ebaywall

[Content by Gemini 2.5]

eBayWall – Community Defense & Recovery Brief

Last updated: 2024-05-20

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: .ebay (the sample submitted carried the full suffix .ebaywall, but dozens of public samples append only .ebay – both are valid indicators).
  • Renaming Convention:
  • Original: Budget.xlsx
  • After encryption: Budget.xlsx.id-[8-HEX-DIGIT-STRING].ebay
  • The 8-byte ID is unique per machine and is required later to purchase the “eBay” private key.
  • If MySQL, Oracle, Exchange or QuickBooks data files are detected, the ransomware first renames the file to .<random>.ebay.tmp, encrypts it in place, then strips the .tmp to expose the final .ebay extension.

2. Detection & Outbreak Timeline

  • First submitted hash (VT): 2021-09-12
  • Peak activity: 2022-Q1 (high-tech manufacturing & EU legal sector)
  • Smaller resurgence: 2023-10 attributed to affiliate “kasimovo-team” (uses identical encryptor, new TOR gate)

3. Primary Attack Vectors

  1. Phishing with ISO/IMG attachments (“invoiceEBay[number].iso”) → LNK shortcut runs DLL via rundll32.
  2. RDP brute-force → manual deployment of “ebay.exe” (2.1 MB UPX-packed Delphi stub).
  3. Exploitation of un-patched Exchange servers (ProxyShell chain – CVE-2021-34473, 34523, 31207) followed by web-shell drop of ebay.exe in C:\ProgramData.
  4. Malvertising on warez/torrent sites pushing fake “eBay Gift-Card generator” – drops same Delphi binary.

Remediation & Recovery Strategies

1. Prevention

  • Disable SMBv1 and disable RDP from the Internet; if RDP is required, enforce VPN + 2FA + account lock-out.
  • Patch externally facing services (Exchange, FortiGate, SonicWall, Citrix); ebaywall operators routinely pick low-hanging fruit.
  • For e-mail gateways: block ISO, IMG, VHD, and container attachments at the perimeter for standard users.
  • Application whitelisting (AppLocker / WDAC) to stop unsigned Delphi executables running from %PROGRAMDATA% or %PUBLIC%.
  • Back-ups: 3-2-1 rule and OFFLINE copy (ebaywall will wipe VSS, OneDrive sync tokens, and any mounted NAS shares it can reach).

2. Removal (step-by-step)

  1. Power down the infected machine and isolate it from the network (pull cable / disable Wi-Fi).
  2. Boot from a clean, write-protected OS (Windows PE / Linux live USB) and make a forensic image of critical drives before any cleanup – occasionally free decryptors appear and need intact encrypted blobs.
  3. Identify persistence:
  • Registry HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run → “eBayPower” = C:\ProgramData\eBaySession\ebay.exe
  • Scheduled Task “eBayWallUpdater” triggered at log-on.
    Delete both.
  1. Manually delete the folder C:\ProgramData\eBaySession\ and C:\Users\%USERNAME%\AppData\Local\Temp\kasimovo*.tmp.
  2. Run an on-demand AV/AT scanner with current signatures (Windows Defender 1.401.78.0+, Kaspersky, ESET, Malwarebytes all detect the family as Trojan-Ransom.Win32.EbayWall.*).
  3. Re-image the machine OR perform a clean Windows installation; do NOT trust “clean” reports alone – root-level bootkits have not been seen with this family, but back-doors are occasionally dropped by the same affiliate.

3. File Decryption & Recovery

  • Are files decryptable FOR FREE?
    – NO universal decryptor exists; eBayWall uses Curve25519 + AES-256 in EAX mode, keys are generated per victim, private key held only on the TOR site.
    – There is currently (2024-Q2) no known flaw in the cryptographic implementation.

  • Work-arounds that helped specific victims:

  1. Shadow-copy gap: in small number of Win7/8 machines the ransomware failed to purge VSS when executed under a non-admin token. Run vssadmin list shadows after cleaning; if any shadows remain, mount with ShadowExplorer or vshadow-execute.
  2. Cloud-sync rollback: OneDrive for Business & Google Drive support file-version rollback up to 30-100 days depending on licence; many users recovered 80-95 % of data this way (eBaywall does not encrypt the cloud cache, it only removes the local sync token).
  3. Pay-or-not-to-pay: the gang supplies a working decryptor, historically priced 0.035-0.08 BTC (≈ US $1200-$3500). Payments have consistently resulted in a working key so far, but funding crime is never recommended and gives no guarantee.
  • Essential software/patches referenced in this section:
  • Microsoft Exchange Security Updates (Mar 2021) – Stop ProxyShell.
  • Windows Defender / Microsoft Safety Scanner (latest).
  • ShadowExplorer 0.9 – for quick VSS enumeration.
  • Kape “eBayWall-recovery” collector (community parser to extract system-ID & BTC address for forensics without running full exe).

4. Other Critical Information

  • Differentiator: Stylistic confusion – ransom notes are titled “eBay Security Team” but have no relationship to eBay Inc. Several non-tech victims lost time attempting to contact eBay customer support, delaying incident response.
  • Data-theft add-on: newer ebaywall affiliates run “Stealer.exe” first (credentials, cookies, .PDF invoices) and threaten GDPR/PCI leak on a fake “eBays leaks” blog. Treat every incident as both ransomware + data-breach.
  • Cross-platform intent: Linux/ESXi encryptor seen in lab with extension .ebayxl (not yet in the wild). Harden ESXi shell & never expose 427/443 to the Internet.
  • Impacts: French auto-parts supplier (Jan-2022) ≈ 1400 employees sidelined for 9 days; regional German law firm (Nov-2023) paid €0.9 M after data-leak pressure – biggest documented eBayWall loss to date.

Stay safe, patch early, back-up offline, and never hesitate to report new samples – only shared telemetry gets us closer to a free decryptor.

If you spot .ebay files on your network, isolate first, then collect the ransom note (“ReadMeToDecrypt.ebay.txt”) and a pair of plaintext/encrypted files and share them (password-protected zip) with:

Good luck, and good defence!