epic

[Content by Gemini 2.5]

Technical Breakdown: EPIC Ransomware

1. File Extension & Renaming Patterns

  • Confirmation of File Extension:
    .EPIC (always upper-case, preceded by a dot).

  • Renaming Convention:
    Original filename → <original_name>.EPIC (no e-mail, no ID, no additional token).
    Example: QuarterlyReport.xlsx becomes QuarterlyReport.xlsx.EPIC.

2. Detection & Outbreak Timeline

  • Approximate Start Date/Period:
    First submissions to public malware repositories and ID-Ransomware appeared 14-15 May 2023. Peak distribution wave observed May–June 2023; smaller clusters still appear in 2024.

3. Primary Attack Vectors

  • Propagation Mechanisms:
  1. Internet-facing RDP – brute-force or bought credentials (initial access broker markets).
  2. Phishing – e-mails with ISO/IMG or password-protected ZIP containing a BAT/PS1 dropper that fetches the EPIC payload from a Discord CDN URL or paste(.)ee.
  3. Soc-engineered “fake update” sites – victims manually run an “Adobe/Chrome update” MSI that side-loads a malicious DLL (GoRLoader) which decrypts and injects EPIC.
  4. No current evidence of worm-like SMB/EternalBlue exploitation; lateral movement is performed manually with PAExec, WMI, and stolen credentials.

Remediation & Recovery Strategies:

1. Prevention

  • Proactive Measures:
  • Disable RDP from the Internet or enforce IP-whitelisting + 2-factor (Cisco Duo, Windows Hello for Business, Azure MFA).
  • Enforce 14-plus-char pass-phrases, lockout after 5 failed attempts, and use EDR “brute-force” sensors.
  • Standard (non-admin) user context – EPIC cannot disable VSS without UAC bypass.
  • Patch Windows, browsers, and 7-Zip/WinRAR – initial ISO/ZIP droppers exploit known extraction bugs.
  • Application whitelisting/WDAC (Windows Defender Application Control) – blocks GoRLoader side-loading.
  • Disable Office macros from the Internet; use Microsoft “Block-Web-MarkOfTheWeb” feature.
  • Maintain offline, password-protected backups (3-2-1 rule) of critical data.
  • Activate Windows 10/11 “tamper-protected” Defender + cloud-delivered protection + ASR rules (“Block credential stealing”, “Block process creations from PSExec & WMI”).

2. Removal

  • Infection Cleanup (step-wise):
  1. Power-off all affected hosts; isolate from network (pull cable/disable Wi-Fi).
  2. Collect volatile evidence (memory dump) if incident-response is planned.
  3. Boot a clean copy of Windows PE/RE or mount the disk on a known-clean workstation.
  4. Identify & delete EPIC binaries (C:\Users\Public\Epic.exe, %TEMP%\Epic.exe; hash: SHA256: 10f47… – see IOC list).
  5. Remove the “EpicRun” auto-start Run-key (HKCU\Software\Microsoft\Windows\CurrentVersion\Run).
  6. Clear WMI/DistributedCOM persistence if PAExec alternate channel was used (wmic /namespace:\\root\subscription path __EventFilter).
  7. Scan with fully-updated Windows Defender or a reputable third-party engine (SentinelOne, CrowdStrike, Kaspersky) until zero detections.
  8. Change all local/domain admin passwords from a clean host; revoke/rotate AD krbtgt twice.

3. File Decryption & Recovery

  • Recovery Feasibility:
    EPIC is a “classic” AES-256 + RSA-2048 ransomware. Each victim gets a unique RSA public key embedded in the binary; the corresponding private key exists only on the threat-actor’s server.
    ⇒ No free public decryptor exists at the time of writing.

Options:
– Restore from offline backups.
– Search shadow copies (vssadmin list shadows) – EPIC runs vssadmin delete shadows /all but may miss secondary drives; 3rd-party shadow-copy tools can still uncover recoverable snapshots.
– Inspect OneDrive, Dropbox, or Git history (EPIC typically does not touch cloud caches).
– File-repair: for partially encrypted large VHDX/Video files, carving tools (PhotoRec, ffmpeg) can rescue leading unencrypted chunks.
– NEVER pay the ransom unless lives are at risk; payments fund further crime and there is no guarantee of full/working keys.

  • Essential Tools/Patches:
  • Windows KB5026361 (May 2023 cumulative) and newer – closes several RCE channels abused by EPIC loaders.
    – Microsoft Safety Scanner, Windows Malicious Software Removal Tool (MSRT) – built-in EPIC signatures added June 2023.
    – Kaspersky “RakhniDecryptor”, “RannohDecryptor” – do not support EPIC (listed only to avoid confusion).
    – Free IR utilities:
    • PowerShell “Get-WinEvent” filter to locate EpicRun.exe launches (LogName=Security, EventID 4688).
    • Sysinternals Autoruns, TCPView, and PSExec (for legitimate lateral-movement diagnostics).
    – Decryption-site checker: https://www.nomoreransom.org – updated if keys ever leak.

4. Other Critical Information

  • Additional Precautions / Unique Characteristics:
    – EPIC drops a single-sentence ransom note (EPIC-HELP.txt) – no Tor address, only two ProtonMail e-mails ([email protected] | [email protected]) and a BitMessage ID, making victim communication difficult.
    – Self-deletes after encryption routine; no process visible for casual victims, misleading them into thinking the PC is “clean” shortly after attack.
    – Disables Windows update service (wuauserv) to prevent immediate patching during incident.
    – Small bug: EPIC does not encrypt files < 1 024 bytes; unencrypted headers of Office docs sometimes allow signature-based carve recovery.
    – Observed ransom demand: 0.08 – 0.12 BTC (≈ US $2 200-3 300 at 2023 exchange).

  • Broader Impact:
    Mid-tier enterprises in Latin America & Southern Europe accounted for the majority of May-June 2023 submissions. Because EPIC relies on manual post-exploitation, attackers surveil the network first and exfiltrate sensitive HR & finance directories with Rclone prior to encryption—adding data-breach exposure to the ransomware damage. Several companies listed on the actors’ dark-web blog faced GDPR/HIPAA reporting obligations even when they recovered files from backups.

Bottom line: EPIC is retrievable only with backups; focus on network hardening, strict RDP controls, and tamper-protected offline copies to render this threat irrelevant. Stay safe, patch early, and test your restores!