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Ransom.Win64.RUTHENS.THLABBC

January 03, 2024
 Analysis by: Francesca Villasanta
 ALIASES:

UDS:Trojan-Ransom.Win64.Hive.a (KASPERSKY); Trojan.Ransom.Hunters.A (BITDEFENDER)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware


This Ransomware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It drops files as ransom note. It avoids encrypting files with the following file extensions.

  TECHNICAL DETAILS

File Size:

635,904 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

09 Nov 2023

Payload:

Disables AV, Encrypts files, Terminates processes

Arrival Details

This Ransomware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Ransomware adds the following processes:

  • wmic.exe shadowcopy delete
  • bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures
  • wbadmin.exe delete systemstatebackup -keepVersions:3
  • wbadmin.exe delete systemstatebackup
  • bcdedit.exe /set {default} recoveryenabled No
  • vssadmin.exe delete shadows /all /quiet
  • wbadmin.exe delete catalog-quiet
  • notepad.exe {Drive}:\Contact Us.txt

Process Termination

This Ransomware terminates the following services if found on the affected system:

  • mepocs
  • memtas
  • veeam
  • svc$
  • backup
  • sql
  • vss
  • msexchange
  • vmm
  • vmwp

It terminates the following processes if found running in the affected system's memory:

  • encsvc
  • thebat
  • mydesktopqos
  • xfssvccon
  • firefox
  • infopath
  • winword
  • steam
  • synctime
  • notepad
  • ocomm
  • onenote
  • mspub
  • thunderbird
  • agntsvc
  • sql
  • excel
  • powerpnt
  • outlook
  • wordpad
  • dbeng50
  • isqlplussvc
  • sqbcoreservice
  • oracle
  • ocautoupds
  • dbsnmp
  • msaccess
  • tbirdconfig
  • ocssd
  • mydesktopservice
  • visio

Other Details

This Ransomware does the following:

  • It accepts the following argument:
    • -c {username}:{password} → Required. Specifies the username and password to access the contact page
    • -a, -attach, --attach → Enables logging
    • -A, -no-aggressive, --no-aggressive → Disables the deletion of backups and recovery
    • -E, -no-extension, --no-extension → Disables appending of extension to files
    • -m, -min-size, --min-size → Specifies the minimum file size for encryption (in bytes)
    • {File or Path to encrypt} → Encrypts a specific file or directory
  • It encrypts fixed, removable, and network drives.

Ransomware Routine

This Ransomware avoids encrypting files with the following strings in their file name:

  • autorun.inf
  • bootfont.bin
  • boot.ini
  • bootsect.bak
  • desktop.ini
  • iconcache.db
  • ntldr
  • ntuser.dat
  • ntuser.dat.log
  • ntuser.ini
  • thumbs.db
  • Contact Us.txt

It avoids encrypting files with the following strings in their file path:

  • perflogs
  • appdata
  • $windows.~bt
  • windows.old
  • $windows.~ws
  • msocache
  • mozilla
  • tor browser
  • $recycle.bin
  • windows
  • windows nt
  • intel
  • all users
  • internet explorer
  • default
  • boot
  • system volume information
  • config.msi
  • google

It appends the following extension to the file name of the encrypted files:

  • {original filename}.{original extension}.locked

It drops the following file(s) as ransom note:

  • {Encrypted Directory}\Contact Us.txt
  • {Drive}:\Contact Us.txt

It avoids encrypting files with the following file extensions:

  • 386
  • adv
  • ani
  • bat
  • bin
  • cab
  • cmd
  • com
  • cpl
  • cur
  • deskthemepack
  • diagcab
  • diagcfg
  • diagpkg
  • dll
  • drv
  • exe
  • hlp
  • hta
  • icl
  • icns
  • ico
  • ics
  • idx
  • key
  • ldf
  • lnk
  • lock
  • mod
  • mpa
  • msc
  • msi
  • msp
  • msstyles
  • msu
  • nls
  • nomedia
  • ocx
  • pdb
  • prf
  • ps1
  • rom
  • rtp
  • scr
  • shs
  • spl
  • sys
  • theme
  • themepack
  • wpx

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

18.874.03

FIRST VSAPI PATTERN DATE:

12 Dec 2023

VSAPI OPR PATTERN File:

18.875.00

VSAPI OPR PATTERN Date:

12 Dec 2023

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     Troj.Win32.TRX.XXPE50FFF075

Step 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 3

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 4

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files and folders in the search result.
  • {Encrypted Directory}\Contact Us.txt
  • {Drive}:\Contact Us.txt

Step 5

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win64.RUTHENS.THLABBC. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check the following Trend Micro Support pages for more information:


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