Ransom.Win32.LOCKBIT.SMYXCJN

 Analysis by: Arianne Grace Dela Cruz

 ALIASES:

Ransom:Win32/Lockbit.HA!MTB (MICROSOFT); UDS:Trojan-Ransom.Win32.Generic (KASPERSKY)

 PLATFORM:

Windows

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

  • Threat Type: Ransomware

  • Destructiveness: No

  • Encrypted: Yes

  • 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 does not have any propagation routine.

It does not have any backdoor routine.

It gathers certain information on the affected computer.

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

  TECHNICAL DETAILS

File Size:

150,528 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

27 Apr 2023

Payload:

Modifies system registry, Terminates processes, Drops files, Steals information

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 mutexes to ensure that only one of its copies runs at any one time:

  • Global\{Generated hash}

Other System Modifications

This Ransomware adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
.fxkJts2wg
(Default) = fxkJts2wg

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
fxkJts2wg\DefaultIcon
(Default) = %ProgramData%\fxkJts2wg.ico

Propagation

This Ransomware does not have any propagation routine.

Backdoor Routine

This Ransomware does not have any backdoor routine.

Process Termination

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

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

Dropping Routine

This Ransomware drops the following files:

  • %ProgramData%\fxkJts2wg.ico

Information Theft

This Ransomware gathers the following information on the affected computer:

  • Hostname
  • Username
  • OS version
  • Domain
  • Architecture
  • Language
  • Disk information (Disk name, Disk size, Disk free size)

Other Details

This Ransomware adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes
.fxkJts2wg =

It does the following:

  • If not executed with admin rights, it will attempt relaunch itself as admin by elevating its privileges via bypassing UAC.
  • It encrypts fixed, removable and network drives
  • It deletes files in recycle bin folder for removable and fixed drives
  • It uses WQL to delete shadow copies
  • It terminates if the machine has the following system language:
    • Arabic (Syria)
    • Armenian
    • Azerbaijani (Cyrillic)
    • Azerbaijani (Latin)
    • Belarusian
    • Georgian
    • Kazakh
    • Kyrgyz (Cyrillic)
    • Romanian (Moldova)
    • Russian
    • Russian (Moldova)
    • Tajik
    • Tatar
    • Turkmen
    • Ukrainian
    • Uzbek (Cyrillic)
    • Uzbek (Latin)
  • It duplicates the token of the following:
    • explorer.exe - to gain privileged domain access
    • lsass.exe
    • TrustedInstaller - service is started if not yet running
  • It deletes the following services:
    • WdBoot
    • WdFilter
    • WdNisDrv
    • WdNisSvc
    • WinDefend
    • wscsvc
    • sppsvc
    • Sense
    • SecurityHealthService
  • It contains a list of username:password that it will use to log into domain controllers.
  • It deletes services with the following strings:
    • backup
    • GxBlr
    • GxCIMgr
    • GxCVD
    • GxFWD
    • GxVss
    • memtas
    • mepocs
    • msexchange
    • sophos
    • sql
    • svc$
    • veeam
    • vss

Ransomware Routine

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

  • autorun.inf
  • boot.ini
  • bootfont.bin
  • bootsect.bak
  • d3d9caps.dat
  • desktop.ini
  • GDIPFONTCACHEV1.DAT
  • iconcache.db
  • ntldr
  • ntuser.dat
  • ntuser.dat.log
  • ntuser.ini
  • thumbs.db

It avoids encrypting files found in the following folders:

  • $recycle.bin
  • $windows.~bt
  • $windows.~ws
  • all users
  • boot
  • config.msi
  • default
  • intel
  • microsoft
  • msocache
  • perflogs
  • program files
  • program files (x86)
  • programdata
  • public
  • system volume information
  • tor browser
  • windows
  • windows.old
  • x64dbg

It renames encrypted files using the following names:

  • {Random Characters}.fxkJts2wg

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

  • {Encrypted Directory}\fxkJts2wg.README.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
  • search-ms
  • shs
  • spl
  • sys
  • theme
  • themepack
  • wpx

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

18.148.05

FIRST VSAPI PATTERN DATE:

22 Dec 2022

VSAPI OPR PATTERN File:

18.149.00

VSAPI OPR PATTERN Date:

23 Dec 2022

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.XXPE50FFF068

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

Restart in Safe Mode

[ Learn More ]

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
    • .fxkJts2wg

Step 6

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.
  • {Encrypted Directory}\fxkJts2wg.README.txt
  • %ProgramData%\fxkJts2wg.ico

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.LOCKBIT.SMYXCJN. 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 this Knowledge Base page for more information.

Step 8

Restore encrypted files from backup.

Step 9

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.LOCKBIT.SMYXCJN. 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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