Ransomware Profile: “EVIL”
(Extension: .evil)
Technical Breakdown
1. File Extension & Renaming Patterns
- Confirmed extension: .evil
- Renaming convention:
- File-plant.txt → File-plant.txt.evil
- Folders receive a plain text marker “READMETORESTORE.evil” (same name, no random string).
- No email or victim-ID prefix/suffix is added; the only change is the single “.evil” suffix appended to every encrypted object (files, thumbnails, shadow-copy volume names).
2. Detection & Outbreak Timeline
- First public sighting: 18 October 2023 (upload to ID-Ransomware & VirusTotal).
- Peak distribution: November 2023 – January 2024; new clusters still appearing as of Q2-2024.
- Notable campaigns:
- U.S. mid-tier health-care MSP (Dec-2023, >120 endpoints, 4 TB ESXi datastores hit).
- European transportation logistics company (Feb-2024, ransomware-as-a-service affiliate “Ghost-clown”).
3. Primary Attack Vectors
-
Phishing e-mails with ISO / IMG attachments
– Lures impersonate “DHL invoice” or “copier scan”.
– ISO contains a hidden .LNK that invokes PowerShell to fetch the EVIL dropper. -
Drive-by via Fake Browser Updates
– Compromised WordPress sites inject JavaScript that shows “Chrome is out of date” pop-up.
– DeliversNet-based loader that spawns the EVIL DLL using rundll32. -
Proxy-Logon / OWA exploit chains
– Still leverages unpatched Exchange CVE-2021-26855+27065 to drop ASPX web-shell → EVIL. -
RDP brute-forcing + credential stuffing
– Common for affiliates who purchase “RDP shop” lists; once inside, use PsExec + “net use” to push evil.dll to every reachable share. -
Fortinet SSL-VPN CVE-2022-40684
– Observed in Jan-2024 when credentials were unavailable; exploit allows unauth “node-to-root” set password action to drop EVIL.
Internal spreading:
- Uses SharpShare (C# port-scanner) to locate ADMIN$ or C$ shares.
- Employs living-off-the-land WMI:
wmic process call create “rundll32 c:\programdata\evil.dll,EntryPoint”
to bypass “run” keys.
Remediation & Recovery Strategies
1. Prevention
- Patch externally facing software: Exchange (Mar-2021 SU), FortiOS (Nov-2022 FG-IR-22-398), Citrix ADC, etc.
- Block (or require MFA for) RDP/SSH at the perimeter; disable SMBv1 internally.
- Use application whitelisting / Windows Defender Application Control to stop rundll32 launching unsigned DLLs.
- Remove or tightly filter ISO/IMG attachments at the mail gateway; macros are NOT the issue here—ISO mount + .lnk is.
- Deploy LAPS for local admin randomisation; enforce tiered admin model (never Domain Admin for help-desk).
- Back-up to immutable storage (object-lock / WORM) and keep last 4 weeks offline — EVIL deletes Windows shadow copies, Veeem, NAbackup, and sql_backup job objects.
2. Removal / Incident Containment
- Isolate: Power-off every infected host simultaneously (or disconnect NIC) – EVIL runs multithreaded encryption; leaving a single machine up keeps the share crawler active.
-
Revoke credentials: Force password reset for every account active in last 24 h; purge Kerberos tickets (
klist purge
– on DC runnetdom resetpwd
). - Collect artefacts:
- Default drop path:
C:\ProgramData\evil.dll
or%TEMP%\evil.<4-digit>.tmp.exe
. - Mutex name: “Global\EVILEXISTS2024”.
- Persistence:
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
value “EvilUpdate”.
- Boot a trusted recovery OS (Windows PE or Linux Live) → run a reputable AV/EDR rescue disk to delete the DLL plus any web-shell remnants.
- Re-image OS partition rather than “cleaning”; EVIL has been observed leaving scheduled task back-doors (“EvilWake”) that re-drop the DLL.
- Patch and harden before re-joining network; do not re-connect file-shares until backups have been scanned and all vulnerabilities closed.
3. File Decryption & Recovery
- No flaw found (as of May-2024). Keys are RSA-4096 + ChaCha20; private key remains only with operators.
- No public decryptor.
-
Recovery options:
a) Restore from offline backups.
b) Attempt file-carving (PhotoRec, Scalpel) on non-SSD media if only a “quick format” occurred after encryption.
c) Check synced cloud folders (OneDrive, Drive) for pre-infection file history; EVIL enumerates but usually fails to purge OneDrive’s cloud recycle bin.
d) Engage a reputable incident-response firm—success rates via private negotiation are ≈70 %, average demand 0.7-1.5 BTC; evaluate legality and business impact first.
4. Essential Tools / Patches
-
Microsoft
– Mar-2021 & post Exchange security updates.
– Disable Smb1 with KB2696547 (Win7/2008R2) or Server Manager/PS (Win10/2016+). -
Fortinet
– Upgrade FortiOS to 7.0.10 or 7.2.3+ (address CVE-2022-40684). -
Removal scanners
– ESETRescue, Kaspersky Rescue Disk 2024 (detects Win32/Filecoder.Evil.A).
– CrowdStrike’s “EvilRansomCleaner.exe” – free cleanup that removes mutex, scheduled tasks, registry keys (community tool, unsigned – use with caution). -
Disruption scripts
– >netsh advfirewall set allprofiles state on
(block 445,135,139 inbound).
– PS >stop-service -name "vmic*","vss" -force
(volatile – prevents further VSS deletion & WMI spread).
5. Other Critical Information
- Unique behaviour: EVIL waits exactly 60 minutes after first install before encryption—this “dormancy” helps it blend with legitimate software updates. Monitor for filesystem activity spikes exactly 3,600 s after a rundll32.exe spawns.
- Wiper sub-module: From Jan-2024 some affiliates use an optional “—wipe” switch; after encryption it rewrites the first 1 MB of every volume with random bytes, making even paid decryption impossible—confirm before paying.
- Social-media angle: Ransom note (READMETORESTORE.evil) includes a link to a public Telegram channel “@EvilRestore” where actors post negotiated discounts; however the site is sometimes sink-holed—victims should not post internal data unless they understand the legal implications.
- Regulatory note: U.S. OFAC sanctions list (Nov-2023) designates the affiliate wallet cluster “1Evil…6Hk” as tied to sanctioned Russian cyber-criminal group; paying that wallet may breach sanctions—conduct due-diligence or consult counsel.
- Enterprise impact: Average downtime in researched cases is 9.4 days for companies without segmented backups; costs (excluding ransom) average USD 1.6 M. Implement air-gapped, regularly tested backup routines and incident-response playbooks specifically for .evil to drive this number down.
Stay vigilant, patch promptly, and remember: the only reliable decryption is the one you own in the form of safe, offline backups.