chipslock

[Content by Gemini 2.5]

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension: All files encrypted by ChipsLock receive the plaintext suffix .chipslock.
  • Renaming Convention: After encryption, every targeted file is renamed according to the pattern
    <original_filename>.id-<unique_victim_ID>.<attacker_email>.chipslock
    Example: 2024-Financial-Report.xlsx.id-B84F2C91B2.grandsupplier@outlook.com.chipslock

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period: First samples submitted to public sandboxes and incident-response portals appeared in the third week of September 2023. Rapid peaks in telemetry were observed from 2 October 2023 through late-December 2023, indicating a coordinated initial seeding campaign.

3. Primary Attack Vectors

  • Propagation Mechanisms:
    • Phishing campaigns with weaponized ZIP or 7z archives (“quotation.zip”, “invoice_2024.7z”) containing a heavily obfuscated .NET executable.
    • RDP brute-force followed by manual deployment – attackers pivot laterally once Domain Admin is achieved.
    • Exploitation of exposed, un-patched remote monitoring and management (RMM) tools (AnyDesk, ScreenConnect, ITarian, Syncro) using stolen 3rd-party vendor credentials.
    • Drive-by download via malicious Google/Bing ads pointing to fake download pages for advanced-IP-scanners and remote-desktop utilities.
    • NO observed EternalBlue/SMB (MS17-010) usage – ChipsLock relies predominantly on credential abuse rather than network-level exploits.

Remediation & Recovery Strategies:

1. Prevention

  • Proactive Measures:
  1. Disable or restrict RDP on all perimeter devices; enforce Network Level Authentication (NLA) and IP whitelists.
  2. Mandate unique, strong passwords for privileged accounts and enable multi-factor authentication (MFA) everywhere (especially M365, VPN, RMM portals).
  3. Patch remote-support software monthly; remove or limit the install footprint of external RMM agents when not needed.
  4. Block email attachments with advanced archive types (.7z, .rar, .img) via mail-gateway policies; route them to behavioral sandboxing.
  5. Enforce application-control/allow-listing (AppLocker, Windows Defender Application Control) preventing .NET PEs from executing from user download folders.
  6. Keep offline, immutable backups (Write-Once, offline S3 with Object Lock, or LTO tapes) and test restores quarterly.
  7. Turn on PowerShell logging and Sysmon Event ID 1/11 to detect the execution -hidden -encodedcommand patterns used by the initial dropper.

2. Removal

  • Infection Cleanup Steps:
  1. Disconnect the host from all networks—unplug Ethernet, disable Wi-Fi/Bluetooth.
  2. Boot into Safe Mode with Networking (or WinPE if domain logon fails) with System Restore disabled.
  3. Identify and kill the persistence binary (<random>.exe or ChipsLock.exe on 32-bit temp folder). Launch Autoruns (Sysinternals) to delete malicious scheduled tasks, Run keys, and WMI event filters.
  4. Check Credential Manager and Registry for dumped credentials; rotate them externally before reconnecting.
  5. Run a full, signature-updated offline scan with Windows Defender Offline, Trend Micro Ransom-ware Remover, or Malwarebytes Boot PE.
  6. Validate absence of volume-shadow delete events in vssadmin list shadows; manually recreate shadow storage if necessary.
  7. Re-join to domain only after GPO hardening and patch level confirmed.

3. File Decryption & Recovery

  • Recovery Feasibility: Decryption is NOT currently possible without the attacker’s private key. ChipsLock uses curve25519 ECDH + AES-256-CBC, with robust key storage and immediate deletion post-execution.
  • Free Decryptor: No public decryptor exists (as of March 2024). Purported “CryptoGuard-C” entries on virus-info forums are scams abusing the brand.
  • Backup Fallback:
    • Ensure offline backups are uninfected; do not recover from backups mounted at infection time—they were deleted and replaced with the .chipslock originals.
    • If Azure/AWS snapshots were present prior to encryption with versioning or immutability, create isolated restore points, then scan recovered volumes fully.
  • Keylessness Mitigation:
    • Only file-set-level recovery via backups, SharePoint versioning, or Exchange mailbox retention on M365 if Shadow Copy wasn’t wiped (occurs in <15 % of real cases).

4. Other Critical Information

  • Unique Characteristics:
    • ChipsLock deliberately skips Windows folder, System32, and recovery partition to keep the OS bootable—maximizing ransom probability.
    • Drops a SHA-512 checksum list (enc_index.json) in %PUBLIC%\Documents to speed selective decryption in partial-payment scenarios.
    • Deletes local Shadow Copies, but leaves network-bound VHD files untouched, highlighting the importance of volume-level snapshots rather than OS-level shadow copies.
  • Broader Impact:
    • Target Profile: SMB healthcare, construction, and logistics verticals—sectors prone to weak RMM practices.
    • Concentrated campaigns in Europe and SE Asia; email lures adopted bilingual business templates (German/English, Korean/English).
    • Second-stage Smishing observed – attackers who receive a partial BTC payment pivot to WhatsApp/Telegram to embarrass the company and demand more money.
    • Splintered affiliate program using ChipsLock: tracking shows at least six separate intrusion sets sharing nearly identical codebases, complicating attribution.

Essential Tools & Patches Download List (March 2024):
• Windows Security Update Feb 2024 (KB5034763) – fixes the CrowdTrove SMB novelty.
• Trend Micro Ransomware Scanner 11.5.1188 – offline boot support.
• Emsisoft Emergency Kit 2024.3 – includes fix for 0-day driver used slipstream by prior affiliates.
• Anydesk v7.1.2 – replaces older versions with known default-credential abuse.
• SumRando VPN was patched in 3.2; prior versions used in affiliate ingress.