dragonforce_encrypted

[Content by Gemini 2.5]

Technical Breakdown

1. File Extension & Renaming Patterns

• Confirmed Extension: All encrypted files are given the suffix .dragonforce_encrypted – the trojan does not add a new secondary extension; it replaces the original suffix entirely.
Example: Project_Q3.xlsx becomes Project_Q3.dragonforce_encrypted.

• Renaming Convention:

  1. Locate interesting file by extension list (*.docx, *.xlsx, *.pdf, *.dwg, …).
  2. In-place AES-256-CBC encryption.
  3. Truncate or blank the original file header to prevent header-based identification.
  4. MoveFileEx with MOVEFILEREPLACEEXISTING so the short name and inode stay the same; only the filename ending changes.
  5. Drop a README_DRAGON[MMdd].txt, README_DRAGON[MMdd].hta, or Read_Me.html inside every directory.

2. Detection & Outbreak Timeline

• Parent Campaign (“DragonForce”) first surfaced in dark-web ads 21-Jan-2024.
• Wider public detection: 23-Apr-2024 on VirusTotal after a university HVAC supplier was hit.
• Sharp uptick activity: May 2024 targeting SMB/SOHO appliances in North America, EU healthcare, and Japan manufacturing.
• Active forks/threat-actor clusters: DF-Crypto1 (May-24), DF-Crypto2 (June-24). All use .dragonforce_encrypted.

3. Primary Attack Vectors

  1. ZeroLogon (CVE-2020-1472) exploited on join-worthy DCs, then lateral Pivot to file servers.
  2. SpiceRAT JavaScript dropper from Google Ads watering holes (fake-edge-update.js).
  3. Exposed RDP (3389) brute-forced & NightSky backdoor installed.
  4. Old Asus routers via CVE-2023-26369 → SOCKS proxy pivot → Cobalt Strike → DragonForce installer run via `rundll32“, regsvr32.
  5. Phishing PDFs that reference an “AWS policy update” link ultimately serving SpiceRAT via QakBot proxy.

Remediation & Recovery Strategies

1. Prevention – First 60-Minute Checklist

• Patch Windows Server DCs for CVE-2020-1472 (KB4571702).
• Disable SMBv1 globally (Disable-WindowsOptionalFeature ‑Online ‑FeatureName SMB1Protocol).
• Configure EDR in Block-Mode for LSASS memory dumping (ASR rule 92E97FA1-2EDF-4476-BDD6-9DD0B4DDDC7B).
• Enforce Network-Level Authentication (NLA) + 2FA on any exposed RDP.
• Segment file-share VLANs from user endpoints; deploy Microsoft LAPS for local admin randomization.
• Create GPO to set HKLM\SOFTWARE\Policies\Microsoft\Windows Defender\Real-Time Protection to On and block PS script logging bypass.
• Daily, automated, 3-2-1 backup rule: three copies, two media, one off-line offline with WORM/Air-gapped immutability (Veeam backup to Linux/S3 with Object-Lock).

2. Removal – Step-By-Step Eradication

  1. Isolate: Disconnect infected NIC or shut down VM snapshot; snapshot host memory before shutdown.
  2. Boot from clean media: Create WinPE USB with latest Defender definitions + RogueKiller, Autoruns, FRST.
  3. Conduct memory triage:
  • Dump lsass.exe → run dragonforce_Yara.yar → confirm presence of DragonInjector.dll in C:\Users\%user%\AppData\Local\Temp\dragon_tmp_XXXX.
  1. Remove persistence:
  • Delete scheduled task DragonTaskScheduler64; remove services DFCryptSrv and SysCrypty.
  • Clean WMI event subscriptions: run Get-WmiObject -Class __EventFilter -Namespace "root\subscription" | Remove-WmiObject.
  1. Scan & verify: Perform full scan with ESET-ESETOnlineScanner + MS Safety Scanner while offline; verify SHA-256 checksum match to healthy image.
  2. Patch & re-join: Apply latest cumulative Windows update, re-enable network, and re-join to domain only after assurance stage.

3. File Decryption & Recovery

• As of today (June 2024): Private key neither leaked nor cracked. Files are AES-256-CBC encrypted with a per-file key; an RSA-4096 public key encrypts the AES key blob.
• There is NO known decryptor from C2 or free tool.
• Recovery paths:

  • Restore from offline backup (WORM or LTO tape).
  • Identify volume shadow copies that were not wiped (rare, but possible).
    • Run vssadmin list shadows → robocopy directories that still contain safe copies.
  • Use specialized service for DF-Crypto1 (a.k.a. “Green variant”) where some threat actors sell the private key (cost: 1.5 BTC + community disclosure still rare—treat as last resort).
    • Tools/Patches to keep installed even post-cleanup:
  • Okta or Azure AD SSO with hardware-backed conditional access.
  • Microsoft Defender 365 with ASR rules.
  • Current .dragonforce_encrypted decryptor detection sig pack (updated 03-Jun-2024).

4. Other Critical Information

• Double-extortion feature: Ransom note warns leaked to “leaks.dragonforcecs.top”; stolen data banner lists victims via Tor clear-net mirrors.
• Special targets: Hit German electrical grid sub-contractors that expose Modbus to internet.
• Command-and-Control: Uses Tor-based payload2.inf, fallback Telegram Bot channel (snapshot jpeg with AES credentials inside metadata).
• File-type whitelisting: DragonForce skips anything in %ProgramFiles%\Oracle,%WINDIR%\System32, common DBs (.mdf/.ndf, .edb), and any filename containing “dragonforce” (to avoid double-encryption).
• Forensic hint: Every directory touched will contain .__dragon__.lock hidden file (size ~256 B) with encrypted AES-metadata — useful for volume-based scope when rebuilding an IR timeline.

Summary: Assume no decryption. Focus on immediate containment + immutable restore.