@wanadecryptor@.*

[Content by Gemini 2.5]

Technical Breakdown:
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  1. File Extension & Renaming Patterns
    • Confirmation of File Extension: .WNCRY or .WCRY added after the original extension (e.g., budget.xlsx.WNCRY).
    • Renaming Convention: Files keep their original name and internal directory structure; the only visible change is the appended “.WNCRY”. Folders also receive the ransom note @[email protected], and the desktop wallpaper is replaced by @[email protected].

  2. Detection & Outbreak Timeline
    • Start Date: 12 May 2017 at 07:44 UTC, with an explosive global propagation wave that peaked before close-of-business on May 12. A kill-switch domain (iuqerfsodp9ifjaposdfjhgosurijfaewrwergwea.com) was registered later that day, dramatically reducing new infections.

  3. Primary Attack Vectors
    • SMBv1 “EternalBlue” exploit (MS17-010) – wormable lateral movement once an initial foothold is gained.
    • Remote Desktop Protocol brute-force used for initial foothold in many documented cases.
    • Phishing e-mails with malicious attachments, often zips containing .exe or double-extension Office droppers.
    • Watering-hole “drive-by” downloads observed against specific regional websites (original outbreak weeks showed additional Flash and Silverlight exploit chains).

Remediation & Recovery Strategies:
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  1. Prevention
    • Patch Windows systems immediately with MS17-010 (and black-list SMBv1 via group policy).
    • Disable SMBv1 across the environment (sc config lanmanworkstation depend= bowser/mrxsmb20/nsi).
    • Segment internal networks; block direct outbound SMB/TCP 445, 139/135.
    • Enforce strong RDP passwords + 2-factor authentication; move RDP behind a VPN or jump host.
    • Feature-locked backup snapshots stored offline or immutable (WORM, S3 Object Lock, GCS Bucket Lock, etc.).
    • Application Control / Allow-listing; use of Microsoft Security Baselines & EMET/ASR rules.
    • Continuous log ingestion + anomaly detection for rapid kill-switch domain lookups (DNS log monitoring).

  2. Removal (step-by-step)

  3. Isolate the host: pull network cable / disable Wi-Fi immediately (Wannacry worm is active).

  4. Identify and terminate MSSECSS.EXE and any spawned taskhsvc.exe, service.exe, @[email protected].

  5. Delete the dropper payloads typically found in:
    • %ProgramData%\{random-name}\taskhsvc.exe
    • %UserProfile%\AppData\Local\Temp\b.wnry, c.wnry

  6. Remove persistence entries:
    • Registry Run key: HKLM\Software\Microsoft\Windows\CurrentVersion\Run valued “taskeche.exe”.
    • Scheduled tasks “Taskee”, “DownloadAgent”.

  7. Deploy a reputable offline-scanner (Kaspersky Virus Removal Tool, Malwarebytes, Microsoft MSERT).

  8. Reboot into Safe-Mode w/ Networking only after confirming traffic-blocking rules are in place, then patch.

  9. File Decryption & Recovery
    • Feasible by design? – YES
    WannaCry uses a dual-layer encryption scheme:
    1. Per-file AES-128 with a 128-bit key that is unique per file.
    2. The AES keys are RSA-2048 encrypted with the attackers’ public key.
    Shortly after the outbreak, release of the private RSA key used for Windows XP SP3 / Windows 7 (x86 & x64) was extracted from memory (source: Adrien Guinet – “Wannakey”) and later automated into “wanadecrypt” / “WannaDecrypt v2” – free tools that can decrypt absolute-disk reads where the memory page containing the key has remained unchanged.
    • Procedure:
    a. Do not power-cycle or wipe the system; keys stay in RAM only.
    b. Image the infected drive bit-for-bit.
    c. Boot a clean machine; run WanaKiwi (compatible w/ WinXP–Win7 x86/x64, memory must not have rebooted) or WannaKey + wanadecrypt lab tools.
    d. Output = recovers raw AES keys → restores unencrypted files.
    • What if RAM is lost? – Fallback to clean backups; the RSA public keys distributed in 2017 remain uncompromised for newer systems (Win8.1/Win10) unless law-enforcement seizes future private keys.

  10. Other Critical Information
    • Double-kill switch: variant 2.1 hard-coded a second domain (ifferfsodp9ifjaposdfjhgosurijfaewrwergwea.com) found in July-2017; continuous passive monitoring of DNS early-warning lists is still recommended.
    • Hidden-Tear ransom note similarity: C2 uses Tor v3 onion addresses; domain generation algorithm (DGA) not part of the 2017 dataset – so DNS blacklist is reliable.
    • Screen-locker style distribution: renders systems practically unusable (>160 file types) and decommissioned shadow copies via vssadmin delete shadows /all /quiet. Maintain nightly VSS chains on isolated storage for secondary recovery.
    • Broader Impact:
    – Estimated 200 000+ machines across 150 countries within the first 24 h; significant collateral impact on critical medical systems (UK NHS), logistics (FedEx), and the world-wide Maersk shipping network (>$300 M loss).
    – Solidified the case for “Patch Tuesday” emergency out-of-band and inspired modern frameworks such as CISA RA (“Ransomware Readiness Assessment”).