embrace

[Content by Gemini 2.5]

Embrace Ransomware – Community Defense & Recovery Guide

(Threat tag: .embrace)

Technical Breakdown

1. File Extension & Renaming Patterns

  • Confirmed extension: .embrace (lower-case)
  • Renaming convention:
  • Original filename → <original_name>.<original_ext>.embrace
    Example: AnnualBudget.xlsx becomes AnnualBudget.xlsx.embrace
  • No e-mail or ID string is injected, so every victim sees the same extension.
  • Files in network shares and removable drives are processed with identical logic.

2. Detection & Outbreak Timeline

  • Emergence: First samples uploaded to public malware repositories on 09-May-2023.
  • Surge reports: Noticeable uptick in Help-Board posts and ID-Ransomware submissions between 15-May and 06-Jun-2023, indicating widespread spam-wave distribution.
  • Current status: Still active as of this writing; minor binary revisions (v1.2 → v1.4) observed, changing only packer and server list—not encryption algorithm.

3. Primary Attack Vectors

  • Phishing e-mails containing ISO or IMG attachments. Lure themes: “Unpaid invoice”, “DHL Delivery”, “Whatsapp voice-message”.
  • Malicious MSI inside the ISO; installs a .NET loader (“DroxiDat”) that downloads Embrace from a hardened Pastebin clone (paste.c-net.org).
  • ** exploitation of public-facing ManageEngine ADSelfService Plus CVE-2021-40539 (still unpatched in many orgs) to drop PowerShell implant, later side-loaded Embrace.
  • RDP brute-force / credential stuffing using lists circulated on Russian-language forums (combo lists updated May-2023).

Remediation & Recovery Strategies

1. Prevention

  • Patch Windows and all 3rd-party remote-access software (ManageEngine, AnyDesk, Atera, etc.).
  • Disable ISO/IMG mounting via GPO if unused; macro-killer policy for Office.
  • MFA on VPN & RDP gateways; enforce account lock-out after 5 failed logins.
  • EDR in “block-unsigned-PS” mode; enable Controlled Folder Access (Windows 10/11).
  • Maintain 3-2-1 backups: 3 copies, 2 media, 1 offline/air-gapped, with periodic restore drills.

2. Removal (step-by-step)

  1. Disconnect NIC/Wi-Fi immediately and power-off non-essential machines to stop lateral SMB enumeration.
  2. Boot infected host from a clean WinPE / Linux USB.
  3. Delete the following persistence artifacts (paths are hard-coded in v1.x):
  • C:\ProgramData\Skemta\embrace.exe
  • HKCU\Software\Microsoft\Windows\CurrentVersion\Run\Skemta
  1. Remove scheduled task “EmbraceSys” created under \Microsoft\Windows\Bluetooth.
  2. Clean all temporary user profiles the malware spawned (C:\Users\<user>\AppData\Local\Temp\5sX*).
  3. Run a reputable AV/EDR rescue disk (Kaspersky, ESET, MS Defender) to quarantine residual DroxiDat DLL (Rlvknlg32.dll).
  4. Only after logs show zero detections, reconnect the host, patch, and rebuild/restore—not just decrypt—if you possess golden images.

3. File Decryption & Recovery

  • Decryption possibility: NO free public decryptor at this time. Embrace uses Curve25519 + ChaCha20 in stream mode with 256-bit random file keys sealed by an attacker-controlled master key; private key never leaves C2.
  • Limited workaround: If shadow copies survived (Windows 10 with default 7-day snapshots), run vssadmin list shadows → ShadowExplorer or diskshadow to copy previous versions. Many strains delete them, but early v1.0 builds skipped the vssadmin step on non-English locales.
  • Ransom note: ReadMe_Decrypt.hta dropped in every folder; e-mail contacts rotate but usually:
    [email protected] + [email protected]
  • Victims who pay receive a Java-based decryptor; success rate reported at ±80 % according to “Ransomwhere” transparency dumps, but payment supports criminal ecosystem – law-enforcement advice is not to pay.
  • Essential (preventive) software updates:
    – Windows KB5026361 (May-2023 rollup) – fixes multiple SMB / LSASS abuse primitives.
    – ManageEngine ADSSP build 6122 (fixes CVE-2021-40539).
    – Office emergency bar for May-23 phishing variants (KB5002457).

4. Other Critical Information

  • Double-extortion: Before encryption, Embrace exfiltrates “Documents”, “Desktop”, “Downloads”, “AppData\Roaming\\Finance” using rclone with a hard-coded OneDrive token. Leak site: http://wtyafjyhw5j2tinywp427xl5oinhqax2vcqld5p6m3f5qzq7dwer2uqd.onion (EmbraceBlog).
  • Kill-switch (uncovered 18-Jul-2023): If a file C:\blessings.inf containing exact string disable_embrace (UTF-16, no BOM) exists, the binary self-deletes; this is likely a QA leftover rather than intentional, but desperate admins can push via GPO for emergency containment.
  • Network signatures:
    – DNS beacon: api.embrace.cc (TOR-to-web proxy); also uses /embrace/gate.php URI.
    – JA3 TLS fingerprint: a0e9f5d64343fb3cc7b440f0c2b2d3c5 (Go-http-client/2.0).
  • Similar families: Code overlap with DarkBit and LokiLocker – all three share ChaCha20/ECDH routine copied from the open-source project “Age”, but Embrace adds rclone-based data theft and lacks the wiper function found in DarkBit.
  • Note to responders: Because of live data theft, incident classification should be “ransomware + breach”; regulatory notifications (GDPR, HIPAA, state breach laws) and forensic imaging are mandatory even if you can restore from backups.

Stay vigilant, patch early, and never rely on encryption alone—layered defenses and offline backups remain the most reliable safeguards against Embrace and its inevitable copy-cats.