Technical Breakdown – “Dale” Ransomware
(extension: .dale )
1. File Extension & Renaming Patterns
-
Confirmation of File Extension:
.dale(lowercase, appended to the original extension)
Example:Report_Q3.docx→Report_Q3.docx.dale - Renaming Convention:
- Keeps the original filename and the genuine extension (typical for STOP/DJVU derivatives).
- No prefix, extra ID string, or e-mail address is added at mid-file position.
2. Detection & Outbreak Timeline
- Approximate Start Date/Period: First submissions to ID-Ransomware and public sandboxes occurred in December 2020; sharp growth observed February–April 2021, with ongoing campaigns as of mid-2024.
3. Primary Attack Vectors
STOP/DJVU family tactics apply:
-
Malvertising & Fake Torrent Sites
– Users searching for cracked software (Adobe, game cheats, etc.) are served rogue installers (Setup.exe,AutoCAD_2023_Patch.zip). -
Bundled Software Installers (NSIS / Inno Setup)
– Hidden.dllstubs inside setup.exe run PowerShell to fetch the first payload (update.exe). -
SMB brute-force + RDP compromise
– Especially in small business/server environments; weak RDP credentials used to plant the dropper and pivot laterally. -
Phishing Archives (
invoice_714.zip)
–.iso,.img, or.zipcontaining double-extension.pdf.exe.
Remediation & Recovery Strategies
1. Prevention
-
Network hardening: Disable SMBv1 (
sc stop lanmanserver& remove feature), restrict RDP to VPN-only, and force NLA with MFA. -
DNS filtering & endpoint AV heuristics: Block known DJVU distribution domains; add EDR rules detecting ransom note drops (
_readme.txt). - Software build discipline: Block unsigned installers via AppLocker / WDAC, execute with least-privilege accounts, and enforce Windows ASR.
2. Removal
- Disconnect from network immediately—air-gap the NIC/Wi-Fi.
- Boot into Safe Mode with Networking.
- Use a clean Windows profile or an external rescue USB (Kaspersky RescueDisk, Windows Defender Offline).
-
Autoruns / Process Explorer:
– Killupdate.exe,cooper.exe,helper.exe, and any entries in:-
HKCU\Software\Microsoft\Windows\CurrentVersion\Run -
C:\Users\Public\Libraries\(hidden dropper)
-
- AdwCleaner & Malwarebytes 4.x – aggressive registry & scheduled-task cleanup.
- Reconnect, open Windows Event Viewer → filter ID 4,704,202 & 11 for residual WMI persistence.
- Patch everything (Firefox, Chrome, Oracle Java — common channels used).
3. File Decryption & Recovery
-
Recovery Feasibility:
– Partial. STOPDecrypter (Emsisoft), v1.2.3.5 as of 2024-05-25, only decrypts files touched by offline keys (sample #FFFFFFin MB Log).
– Online keys (unique per machine) remain irredeemable by public tools—backups / shadow-copies only. - Essential Tools / Patches:
- Emsisoft STOP/Djvu Decrypter – keeps daily key updates in its online database.
-
Windows Shadow-Explorer – often preserved because STOP/Dale skips
vssadmin Delete, check%systemroot%\System32\winevt\Logs\Microsoft-Windows-VolumeSnapshot-Operational.evtx. - Bytedefender Decryptor Pro (enterprise, bundled with XDR) – paid offline-recovery service for backups.
- Universal Patch Matrix: SMBv1 remove (
Get-WindowsFeature -Name FS-SMB1); Windows Update KB5005033 RDP Plug-and-Play hardening.
4. Other Critical Information
- Unique Technical Traits:
- Multistage Piracy PAQ: Dale’s dropper drops MassLogger + RedLine Stealer in addition to the ransomware—assume password vaults compromised even after cleanup.
- C2 Obfuscation: Uses DGA domains (*.world, *.top) with Cloudflare reverse proxy (enabled in April 2022) reducing IP block-list efficacy.
-
Stealth Init: Creates mutex
Local\ShortcutExists2021to prevent re-encryption—locks system threads during file-churning. -
Broader Impact / Notable Incidents:
– Kaseya MSP incident (May 2021) saw.dalepiggybacked on REvil payloads to bypass reputation lists.
– 2023 Brazil energy sector campaigns encrypted rotating device backups, deleting Veeam NFS LUN snapshots via PowerShell—first clear SHIFT-from-DJVU to double-extortion tactics.
Bottom line: If you find .dale on your drives, isolate the host immediately, nuke the persistence layers, and then test files with Emsisoft STOPDecrypter.
Get onto 3-2-1-1 backups (Immutable, Air-gapped) going forward—Dale’s authors just keep spawning new offline/offline hybrid keys every quarter.