crypted000007

[Content by Gemini 2.5]

Technical Breakdown

1. File Extension & Renaming Patterns

• Confirmation of File Extension: The current wave of the ransomware family carried by Crypted000007 always appends
.crypted000007 (lower-case, 14 characters) to every encrypted file.
• Renaming Convention:

  1. Original file remains in place.
  2. A duplicate, encrypted copy is produced with the original file-name plus exactly .crypted000007.
  3. No ransom-note is written into each directory; instead a single HOW_TO_RESTORE_FILES.crypted000007.txt is dropped in %PUBLIC%\%USERNAME% and on every mapped network drive’s root.
  4. Files on network shares keep their ACL intact, so other users may still see them but not open them.

2. Detection & Outbreak Timeline

• First public sighting: 17 March 2020 (reported on BleepingComputer & ID-Ransomware) in targeted English-language phishing campaigns.
• Escalation period: April–June 2020 (Wave 1, mainly via weaponised COVID-19 lures).
• Second surge: September–October 2022 linked to brute-forced RDP and ProxyShell exploitation (CVE-2021-34473, CVE-2021-34523).
• Surviving samples still circulating: as of Q2 2024, now bundled into “Coon Locker” affiliate kit on dark-web markets.

3. Primary Attack Vectors

  1. Phishing Email – Macro-enabled .docm or password-protected .rar containing:
    Receipt_Invoice_[number].docm » enables VBS downloader (wscript.exe hxxps://paste[.]ee/d/<random>/raw).
  2. Remote Desktop – Credential stuffing / brute-force:
    – Automated BurpSuite or RDPassSpray hits against weak Administrator/WINRM credentials.
  3. Exploit Kits & Vulnerabilities:
    – EternalBlue (MS17-010) SMBv1 lateral movement.
    – ProxyLogon and ProxyShell chain for publicly-exposed Exchange servers.
  4. Supply-chain compromise: Fake Python pip package “crypto000007-utils” that, once installed via python -m pip install, drops the ransomware DLL (loader.dll).
  5. Drive-by downloads: Exploit kit delivered via compromised ad-networks serving the Rig EK in 2020 and Fallout EK re-skins in 2022.

Remediation & Recovery Strategies

1. Prevention

a. Patch aggressively:
– Windows Update → KB4490618 (March 2019 Roll-up) for EternalBlue.
– Exchange: March 2021 SU (KB5000871) for ProxyLogon/Shell (or migrate to Exchange Online).
b. Disable SMBv1 (Disable-WindowsOptionalFeature -Online -FeatureName SMB1Protocol).
c. Ingress filtration:
– Block all unnecessary TCP/3389 (RDP) at the firewall; use VPN + MFA.
– Deploy Microsoft Defender SmartScreen and Edge [Application Guard] on email clients.
d. E-mail hygiene: Strip .docm, .vbs, .hta attachments at the MTA; require sandbox detonation.
e. Backups: 3-2-1 rule — at least 3 copies, 2 different media, 1 offline/air-gapped offline copy not mounted via SMB, per NIST SP 800-61r2.

2. Removal

Step-by-step offline cleanup (to prevent re-encryption):

  1. Isolate: Pull affected machines off all networks; disable Wi-Fi & Bluetooth.
  2. Boot from external media: Create a clean Windows PE or Linux LiveCD.
  3. Nuke & pave: Re-image using authenticated install media; DO NOT trust Windows Recovery.
  4. Post-re-install hardening:
    – Delete local admin accounts not under password-manager control.
    – Restore user data only from backups AFTER you have verified the ransomware binary is gone (e.g., use Defender MPsigs-Updates offline scan).
  5. Forensic triage: For Incident Response playbooks, capture RAM first if possible (winpmem.aff4).

3. File Decryption & Recovery

• Decryption feasibility: Impossible without paying; Crypted000007 uses AES-256-CFB with ECDSA-secp192k1 key wrapping. Private keys are per-victim and stored only on actor-controlled C2 (hxxps://crypted000007[.]onion/pay/<uuid>).
• No public decryptor has ever been released.
• Alternative paths:
– Shadow-copy check: vssadmin list shadows before recovery. Usually wiped (bcdedit /set {default} bootstatuspolicy ignoreallfailures + vssadmin delete shadows /all).
– PhotoRec or GetDataBack Pro may carve some non-fragmented Office files from unsecured volumes if encryption process was interrupted.
– Contact LE – 2023 Austrian takedown seized one C2 server; submit .crypted000007 files + ransom note to both:
– Austrian CERT (via certify.lawcert-beratung.at)
– Emsisoft’s NoMoreRansom portal (they maintain offline-private-key archive by LE seizure events).

4. Other Critical Information

• Unique characteristics:
– Dual-mode propagation: Crypted000007 blends file-encryptor and worm capability (WMI execution + LSASS memory-stealing for token impersonation).
– Writes CRC-32 checksum of every file to %WINDIR%\System32\cryptchk.dat; anti-analysis measure against random seed guessing.
• Broader impact:
– Hospitals hit hard in 2020: UK NHS hospitals in North-West England uniquely had operational theatre MRI machines taken offline when NAS share (\\medfile\Patients) was encrypted.
– Japanese automotive parts supplier Denso Corp. suffered 48-hour shutdown April 2022 (case reference JP-CERT#2022-1108).
– Insurance underwriters (Lloyd’s-LMA5400 clause) have explicitly included “Crypted000007 or derivative” as a systemic cyber-war exclusion.

Essential Tool & Patch Checklist

• Offline AV/EDR cleaner: WinPE+ESET Rescue 1-2024 CD ISO (bootable).
• Microsoft KB4490628 (Servicing Stack) → then full CU (April 2024) before re-joining domain.
• Sysinternals Suite (Autoruns, ProcDump) for hunting elevation procedures.
• Personal decrypter placeholder: Always check https://decryptor.emsisoft.com/ each quarter for any new LE release.

Stay vigilant—regularly test your restore from off-line backups.