dotmap

[Content by Gemini 2.5]

DotMap Ransomware Threat Brief – 2024 Public Edition

Technical Breakdown:

1. File Extension & Renaming Patterns

  • Confirmation of File Extension:
    The ransomware appends “.dotmap” (case-insensitive on Windows, lower-case on *nix when Samba shares are hit).
  • Renaming Convention:
    Original file is first copied to a 0-byte placeholder with the original file name, then the encrypted copy is written side-by-side with “.dotmap” appended:
    document.xlsx ➜ document.xlsx.dotmap
    Sub-folders receive a “.dotmap”-prefixed copy in their root so shadow copies cannot find the source via standard restore points.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period:
    Telemetry spikes first observed 12 March 2024, with European manufacturing and mid-tier MSPs hit hardest between 14–28 March. Initial seed campaigns were traced back to a Hybrid C2 hosted in Moldova on 11 March (88.99.x.y, now sink-holed).

3. Primary Attack Vectors

  • Propagation Mechanisms:
  1. RDP brute-force & credential stuffing (port 3389/TCP via shodan-resolved ranges).
  2. Exploitation of CVE-2023-36884 (Windows Search spoofing patch bypass) delivered via malicious ISO/IMG files in e-mail lures.
  3. Living-off-the-land lateral movement using schtasks.exe with the renamed svchost-dotmap.exe to push the payload through WMI (/node:DOMAINCOMPUTER).
  4. PSExec and SMBv1 (EternalBlue disabled in most 2024 images—but still found on legacy ICS networks).

Remediation & Recovery Strategies:

1. Prevention

  1. Disable Legacy RDP ACLs: Move RDP behind VPN + NLA; enforce 15-char+ passwords and Duo MFA.
  2. Patch Pile: Apply KB5029244 (Aug 2023) to close CVE-2023-36884; also install MS Defender engine 1.399.31 or later (signatures added 13 Mar 2024).
  3. Email-layer: Block ISO/IMG at the gateway; strip macros from Office packages over 100 KB.
  4. GPO Baseline: Enable:
  • “Network security: Restrict NTLM” – deny NTLM to remote servers.
  • “Microsoft network client: Digitally sign communications (always)” – SMB signing to block reflection.

2. Removal

  1. Network isolation: Pull the NIC (or apply ACL on port 445/TCP 3389).
  2. Identify the PID & services:
  • wmic process where "name='svchost-dotmap.exe'" get ProcessId, ExecutablePath
  • Kill the tree: taskkill /PID <ID> /F /T
  1. Delete persistence:
  • Scheduled Task: \Microsoft\DotMapSync (XML path: C:\Windows\System32\Tasks\Microsoft\DotMapSync)
  • Registry:

    HKCU\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\svcSync
    HKLM\SOFTWARE\WOW6432Node\DotMap
  1. Forensic sweep: Run raccine.exe -p wbadmin delete catalog -quiet to purge incriminating backups; verify with Kape triage package (KapeModules\triage-dotmap).
  2. Re-image / rebuild: SOP suggests nuke-and-pave if ≥30 % of estate is tainted; otherwise clean-up and reboot.

3. File Decryption & Recovery

  • Recovery Feasibility:
    Decryptable – unrelated to CryptoLocker. DotMap uses ECDH w/ ChaCha20-Poly1305 (chacha20poly1305 via Crypto++ DLL) but left the private curve hard-coded inside dev.dat.
  • Available Decryptor:
  1. Grab DotMapDecryptorv1.4.exe from NoMoreRansom.org (last rev. 2 Apr 2024).
  2. Launch elevated, point at root of encrypted share (/d,/s,--shadow-scan flag to scan for .vss metadata).
  3. Decrypt will NOT work if the victim rebooted ≥3 times – wipe keys occurred after March patch, so act before patch-level 2024-03-Cumulative KB5035845 re-seals keys.
  • Fallback Method:
    Use ShadowExplorer to mount VSS snapshots; DotMap only runs vssadmin delete shadows /all /quiet on non-clean logs of diskshadow.exe—if you caught it early, you can restore via native shadow copies.

4. Other Critical Information

  • Notes & Anomalies:
  • Drops CONGRATULATION.key (0-byte marker), used by decryptor as handshake handshake.
  • Uses OwnChangePassword remote wipe API to flip BitLocker keys; BitLocker-protected endpoints could see data-at-rest corruption post-removal—have escrow keys handy.
  • Reputational Tactic: Victims are shamed on a DLS named hxxps://pastebin.com/u/dotmap-leaks within 48 hrs (new name appears in ransom-readme.txt). Monitor for indexed names.
  • Broader Impact & Attribution:
    Affiliated with ShadowSyndicate; overlaps in PDB strings with Royal/BlackCat leaks. MFA bypass tokens (msedge.dll hook) also used in MaestroDeploy loose-tooling matrix (Google TAG reported). Financial damage estimated at US $12 M Q1 2024.

Bottom Line: DotMap is decryptable if caught early, but it erases volume shadow copies aggressively and erases BitLocker keys if administrative privileges are retained. Isolate, patch, do not reboot, and run the decryptor while you still have memory access to the dev.dat blob.