Ransom.Win32.EMPIRE.THAOBBD

January 11, 2024
 Analysis by: Melvin Jhun Palbusa
 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted:

  • 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 encrypts files with specific file extensions. It encrypts files found in specific folders. It drops files as ransom note.

  TECHNICAL DETAILS

File Size:

204,625 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

02 Jan 2024

Payload:

Encrypts files, Modifies system registry

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:

  • Notepad %Desktop%\HOW-TO-DECRYPT.txt
  • "vssadmin.exe" delete shadows /all /quiet
  • "Wbadmin.exe" DELETE SYSTEMSTATEBACKUP
  • "Wbadmin.exe" DELETE SYSTEMSTATEBACKUP -deleteOldest
  • "cmd.exe" /c vssadmin delete shadows /all /quiet
  • Cmd.exe /c wmic shadowcopy delete
  • Cmd.exe /c bcdedit /set {default} bootstatuspolicy ignoreallfailures
  • Cmd.exe /c bcdedit /set {default} recoveryenabled no
  • Cmd.exe /c wbadmin delete catalog -quiet
  • Cmd.exe /C choice /C Y /N /D Y /T 1 & Del {Malware File Path}

(Note: %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\Desktop on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • ntyUBXFQTHyHkrn

Other System Modifications

This Ransomware adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableRegistryTools = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = 1

Other Details

This Ransomware adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System

It does the following:

  • After its encryption, it display its ransom note
  • Delete System Restore point
  • Terminates itself if mutex is not created
  • Connects to the following URL to send Keys(Password, Hwid, Salt):
    • https://{BLOCKED}54.xsph.ru/one.php
  • It also encrypt removable and fixed drives

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .txt
  • .TXT
  • .jar
  • .exe
  • .dat
  • .contact
  • .settings
  • .doc
  • .docx
  • .xls
  • .xlsx
  • .ppt
  • .pptx
  • .odt
  • .jpg
  • .png
  • .jpeg
  • .gif
  • .csv
  • .py
  • .sql
  • .mdb
  • .sln
  • .php
  • .asp
  • .aspx
  • .html
  • .htm
  • .css
  • .md
  • .rtf
  • .yaml
  • .conf
  • .json5
  • .xml
  • .psd
  • .pdf
  • .dll
  • .c
  • .cs
  • .vb
  • .vbs
  • .p12
  • .mp3
  • .mp4
  • .f3d
  • .dwg
  • .cpp
  • .h
  • .chm
  • .chw
  • .msi
  • .zip
  • .rar
  • .mov
  • .rtf
  • .bmp
  • .mkv
  • .avi
  • .apk
  • .lnk
  • .iso
  • .7z
  • .ace
  • .arj
  • .bz2
  • .cab
  • .gzip
  • .gz
  • .tgz
  • .tar.gz
  • .tbz2
  • .tar.bz2
  • .txz
  • .tar.xz
  • .bkf
  • .tar.zip
  • .tar.7z
  • .tib
  • .gho
  • .bak
  • .ab
  • .vbk
  • .scr
  • .fbl
  • .dmp
  • .tmp
  • .wps
  • .com
  • .bat
  • .cmd
  • .msp
  • .cpl
  • .ps1
  • .vbs
  • .js
  • .wsf
  • .cmdx
  • .lzh
  • .tar
  • .uue
  • .xz
  • .z
  • .001
  • .mpeg
  • .mp3
  • .mpg
  • .core
  • .crproj
  • .pdb
  • .ico
  • .pas
  • .db
  • .torrent
  • .sqlite
  • .mysql
  • .dbf
  • .json
  • .postgresql
  • .oracle
  • .nosql
  • .wim
  • .cur
  • .sdb
  • .xsd
  • .mui
  • .log
  • .rsm

It encrypts files found in the following folders:

  • %User Profile%

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

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

  • %Desktop%\HOW-TO-DECRYPT.txt

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

18.916.03

FIRST VSAPI PATTERN DATE:

02 Jan 2024

VSAPI OPR PATTERN File:

18.917.00

VSAPI OPR PATTERN Date:

03 Jan 2024

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 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.  
  • %Desktop%\HOW-TO-DECRYPT.txt

Step 5

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System

Step 6

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    • DisableRegistryTools=1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
    • DisableTaskMgr=1

Step 7

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.EMPIRE.THAOBBD. 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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