Ransom.MSIL.SMINAJ.THCOFBD

March 13, 2024
 Analysis by: Francesca Villasanta
 ALIASES:

UDS:Trojan-Ransom.MSIL.Gen.gen (KASPERSKY)

 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 encrypts files with specific file extensions. It drops files as ransom note.

  TECHNICAL DETAILS

File Size:

439,296 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

05 Mar 2024

Payload:

Drops files, 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 drops and executes the following files:

  • %User Temp%\{6 Random Characters}.bat → used to delete the Ransomware sample and this batch file

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

It adds the following processes:

  • vssadmin.exe Delete Shadows /All /Quiet
  • bcdedit.exe /set {default} recoveryenabled No
  • bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures
  • wbadmin DELETE SYSTEMSTATEBACKUP
  • wbadmin DELETE sYSTEMSTATEBACKUP-deleteOldest
  • wmic.exe SHADOWCOPY /nointeractive
  • wevtutil.exe cl "{Logname}" → clears event logs
    Lognames:
    • ACEEventLog
    • Application
    • HardwareEvents
    • Internet Explorer
    • Key Management Service
    • Media Center
    • Microsoft-Windows-API-Tracing/Operational
    • Microsoft-Windows-AppID/Operational
    • Microsoft-Windows-Application-Experience/Problem-Steps-Recorder
    • Microsoft-Windows-Application-Experience/Program-Compatibility-Assistant
    • Microsoft-Windows-Application-Experience/Program-Compatibility-Troubleshooter
    • Microsoft-Windows-Application-Experience/Program-Inventory
    • Microsoft-Windows-Application-Experience/Program-Telemetry
    • Microsoft-Windows-AppLocker/EXE and DLL
    • Microsoft-Windows-AppLocker/MSI and Script
    • Microsoft-Windows-Audio/CaptureMonitor
    • Microsoft-Windows-Audio/Operational
    • Microsoft-Windows-Authentication User Interface/Operational
    • Microsoft-Windows-Backup
    • Microsoft-Windows-BitLocker-DrivePreparationTool/Admin
    • Microsoft-Windows-BitLocker-DrivePreparationTool/Operational
    • Microsoft-Windows-Bits-Client/Operational
    • Microsoft-Windows-Bluetooth-MTPEnum/Operational
    • Microsoft-Windows-BranchCache/Operational
    • Microsoft-Windows-BranchCacheSMB/Operational
    • Microsoft-Windows-CodeIntegrity/Operational
    • Microsoft-Windows-CorruptedFileRecovery-Client/Operational
    • Microsoft-Windows-CorruptedFileRecovery-Server/Operational
    • Microsoft-Windows-DateTimeControlPanel/Operational
    • Microsoft-Windows-DeviceSync/Operational
    • Microsoft-Windows-Dhcp-Client/Admin
    • Microsoft-Windows-DhcpNap/Admin
    • Microsoft-Windows-Dhcpv6-Client/Admin
    • Microsoft-Windows-Diagnosis-DPS/Operational
    • Microsoft-Windows-Diagnosis-PCW/Operational
    • Microsoft-Windows-Diagnosis-PLA/Operational
    • Microsoft-Windows-Diagnosis-Scheduled/Operational
    • Microsoft-Windows-Diagnosis-Scripted/Admin
    • Microsoft-Windows-Diagnosis-Scripted/Operational
    • Microsoft-Windows-Diagnosis-ScriptedDiagnosticsProvider/Operational
    • Microsoft-Windows-Diagnostics-Networking/Operational
    • Microsoft-Windows-Diagnostics-Performance/Operational
    • Microsoft-Windows-DiskDiagnostic/Operational
    • Microsoft-Windows-DiskDiagnosticDataCollector/Operational
    • Microsoft-Windows-DiskDiagnosticResolver/Operational
    • Microsoft-Windows-DriverFrameworks-UserMode/Operational
    • Microsoft-Windows-EapHost/Operational
    • Microsoft-Windows-EventCollector/Operational
    • Microsoft-Windows-Fault-Tolerant-Heap/Operational
    • Microsoft-Windows-FMS/Operational
    • Microsoft-Windows-Folder Redirection/Operational
    • Microsoft-Windows-Forwarding/Operational
    • Microsoft-Windows-GroupPolicy/Operational
    • Microsoft-Windows-Help/Operational
    • Microsoft-Windows-HomeGroup Control Panel/Operational
    • Microsoft-Windows-HomeGroup Listener Service/Operational
    • Microsoft-Windows-HomeGroup Provider Service/Operational
    • Microsoft-Windows-IKE/Operational
    • Microsoft-Windows-International/Operational
    • Microsoft-Windows-International-RegionalOptionsControlPanel/Operational
    • Microsoft-Windows-Iphlpsvc/Operational
    • Microsoft-Windows-Kernel-EventTracing/Admin
    • Microsoft-Windows-Kernel-Power/Thermal-Operational
    • Microsoft-Windows-Kernel-StoreMgr/Operational
    • Microsoft-Windows-Kernel-WDI/Operational
    • Microsoft-Windows-Kernel-WHEA/Errors
    • Microsoft-Windows-Kernel-WHEA/Operational
    • Microsoft-Windows-Known Folders API Service
    • Microsoft-Windows-LanguagePackSetup/Operational
    • Microsoft-Windows-MCT/Operational
    • Microsoft-Windows-MemoryDiagnostics-Results/Debug
    • Microsoft-Windows-MUI/Admin
    • Microsoft-Windows-MUI/Operational
    • Microsoft-Windows-NCSI/Operational
    • Microsoft-Windows-NetworkAccessProtection/Operational
    • Microsoft-Windows-NetworkAccessProtection/WHC
    • Microsoft-Windows-NetworkLocationWizard/Operational
    • Microsoft-Windows-NetworkProfile/Operational
    • Microsoft-Windows-NlaSvc/Operational
    • Microsoft-Windows-NTLM/Operational
    • Microsoft-Windows-OfflineFiles/Operational
    • Microsoft-Windows-ParentalControls/Operational
    • Microsoft-Windows-PeopleNearMe/Operational
    • Microsoft-Windows-PowerShell/Operational
    • Microsoft-Windows-PrintService/Admin
    • Microsoft-Windows-ReadyBoost/Operational
    • Microsoft-Windows-ReadyBoostDriver/Operational
    • Microsoft-Windows-Recovery/Operational
    • Microsoft-Windows-ReliabilityAnalysisComponent/Operational
    • Microsoft-Windows-RemoteApp and Desktop Connections/Admin
    • Microsoft-Windows-RemoteAssistance/Admin
    • Microsoft-Windows-RemoteAssistance/Operational
    • Microsoft-Windows-Resource-Exhaustion-Detector/Operational
    • Microsoft-Windows-Resource-Exhaustion-Resolver/Operational
    • Microsoft-Windows-Resource-Leak-Diagnostic/Operational
    • Microsoft-Windows-RestartManager/Operational
    • Microsoft-Windows-Security-Audit-Configuration-Client/Operational
    • Microsoft-Windows-TerminalServices-LocalSessionManager/Admin
    • Microsoft-Windows-TerminalServices-LocalSessionManager/Operational
    • Microsoft-Windows-TerminalServices-PnPDevices/Admin
    • Microsoft-Windows-TerminalServices-PnPDevices/Operational
    • Microsoft-Windows-TerminalServices-RDPClient/Operational
    • Microsoft-Windows-TerminalServices-RemoteConnectionManager/Admin
    • Microsoft-Windows-TerminalServices-RemoteConnectionManager/Operational
    • Microsoft-Windows-TZUtil/Operational
    • Microsoft-Windows-UAC/Operational
    • Microsoft-Windows-UAC-FileVirtualization/Operational
    • Microsoft-Windows-User Profile Service/Operational
    • Microsoft-Windows-VDRVROOT/Operational
    • Microsoft-Windows-VHDMP/Operational
    • Microsoft-Windows-WER-Diag/Operational
    • Microsoft-Windows-WFP/Operational
    • Microsoft-Windows-Windows Defender/Operational
    • Microsoft-Windows-Windows Defender/WHC
    • Microsoft-Windows-Windows Firewall With Advanced Security/ConnectionSecurity
    • Microsoft-Windows-Windows Firewall With Advanced Security/Firewall
    • Microsoft-Windows-WindowsBackup/ActionCenter
    • Microsoft-Windows-WindowsSystemAssessmentTool/Operational
    • Microsoft-Windows-WindowsUpdateClient/Operational
    • Microsoft-Windows-Winlogon/Operational
    • Microsoft-Windows-WinRM/Operational
    • Microsoft-Windows-Winsock-WS2HELP/Operational
    • Microsoft-Windows-Wired-AutoConfig/Operational
    • Microsoft-Windows-WLAN-AutoConfig/Operational
    • Microsoft-Windows-WPD-ClassInstaller/Operational
    • Microsoft-Windows-WPD-CompositeClassDriver/Operational
    • Microsoft-Windows-WPD-MTPClassDriver/Operational
    • ODiag
    • OSession
    • Security
    • Setup
    • System
    • Windows PowerShell

It creates the following folders:

  • %Public%\Windows\Ui

(Note: %Public% is the folder that serves as a repository of files or folders common to all users, which is usually C:\Users\Public in Windows Vista, 7, and 8.)

Process Termination

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

  • postg
  • mysql
  • sqls
  • sqlw
  • onenote
  • outlook
  • exchange
  • visio
  • oracle
  • powerpnt
  • mydesk
  • excel
  • word
  • vivo

Ransomware Routine

This Ransomware encrypts files with the following extensions:

  • .wim
  • .dmp
  • .myo
  • .fdb
  • .key
  • .kdbx
  • .prc
  • .arw
  • .sv2i
  • .v2i
  • .xva
  • .tm
  • .rec
  • .mts
  • .MTS
  • .frm
  • .myi
  • .vhdx
  • .rdpv
  • .ezip
  • .sshv
  • .edb
  • .bco
  • .vbm
  • .vbk
  • .vib
  • .img
  • .7z
  • .aac
  • .accdb
  • .accde
  • .accdr
  • .accdt
  • .adt
  • .adts
  • .aif
  • .aifc
  • .aiff
  • .asp
  • .aspx
  • .avi
  • .bak
  • .bmp
  • .cda
  • .classpath
  • .cpp
  • .cs
  • .csv
  • .dart
  • .dat
  • .dif
  • .doc
  • .docm
  • .docx
  • .dot
  • .dotx
  • .eml
  • .eps
  • .flv
  • .gitignore
  • .go
  • .gz
  • .h
  • .htm
  • .html
  • .ibd
  • .java
  • .jpeg
  • .jpg
  • .js
  • .json
  • .jsp
  • .kt
  • .lua
  • .m4a
  • .mdb
  • .mdf
  • .ldf
  • .mov
  • .mp3
  • .mp4
  • .mpeg
  • .mpg
  • .myd
  • .pdf
  • .php
  • .pl
  • .png
  • .pot
  • .potm
  • .potx
  • .ppam
  • .pps
  • .ppsm
  • .ppsx
  • .ppt
  • .pptm
  • .project
  • .psd
  • .pst
  • .pub
  • .py
  • .rar
  • .rb
  • .rs
  • .rtf
  • .scala
  • .sh
  • .sldm
  • .sldx
  • .sql
  • .svn
  • .swf
  • .swift
  • .tar
  • .vb
  • .vob
  • .vsd
  • .vsdm
  • .vsdx
  • .vss
  • .vssm
  • .vst
  • .vstm
  • .vstx
  • .wav
  • .wbk
  • .wks
  • .wma
  • .wmd
  • .wms
  • .wmv
  • .wmz
  • .wp5
  • .wpd
  • .xla
  • .xlam
  • .xls
  • .xlsm
  • .xlsx
  • .xlt
  • .xltm
  • .xltx
  • .xps
  • .mxf
  • .3g2
  • .3gp
  • .7z
  • .aac
  • .ac3
  • .aep
  • .aepx
  • .aet
  • .aif
  • .aifc
  • .aiff
  • .amr
  • .ape
  • .arc
  • .arj
  • .asf
  • .asp
  • .aspx
  • .asx
  • .au
  • .avi
  • .b64
  • .bat
  • .bh
  • .bmp
  • .btoa
  • .bz2
  • .c
  • .cab
  • .caf
  • .cda
  • .CDDA
  • .cdr
  • .cfg
  • .chm
  • .cpp
  • .cpt
  • .cptx
  • .cr2
  • .csh
  • .css
  • .csv
  • .cue
  • .dat
  • .db
  • .dbf
  • .dds
  • .deb
  • .divx
  • .dmg
  • .doc
  • .docx
  • .dot
  • .dotx
  • .dpx
  • .dss
  • .dst
  • .dts
  • .dv
  • .DWG
  • .dwg
  • .dxf
  • .eac3
  • .eml
  • .eps
  • .flac
  • .fli
  • .flv
  • .gif
  • .gz
  • .gzip
  • .hqx
  • .htm
  • .html
  • .iff
  • .indd
  • .iso
  • .jar
  • .java
  • .jpeg
  • .jpg
  • .js
  • .json
  • .jsp
  • .jspx
  • .kdc
  • .log
  • .ltx
  • .m2a
  • .m2v
  • .m3u
  • .m4a
  • .m4b
  • .m4p
  • .m4r
  • .m4v
  • .max
  • .md
  • .mdb
  • .mef
  • .mht
  • .mhtml
  • .mid
  • .MIDI
  • .midi
  • .mjs
  • .mkv
  • .mov
  • .mp2
  • .mp3
  • .mp4
  • .mpc
  • .mpeg
  • .mpg
  • .mrw
  • .msv
  • .nb
  • .nef
  • .nrw
  • .odb
  • .odf
  • .odg
  • .odp
  • .ods
  • .odt
  • .ogg
  • .ogm
  • .ogv
  • .oma
  • .omg
  • .opus
  • .orf
  • .ost
  • .otf
  • .pac
  • .pages
  • .pb
  • .pbk
  • .pcast
  • .pdf
  • .pef
  • .php
  • .pl
  • .pls
  • .png
  • .ppt
  • .pptx
  • .ps
  • .psd
  • .PST
  • .pst
  • .pub
  • .pva
  • .py
  • .qt
  • .ra
  • .ram
  • .rar
  • .raw
  • .rb
  • .rm
  • .rmi
  • .rmvb
  • .rtf
  • .rw2
  • .rwl
  • .shtml
  • .snd
  • .spx
  • .sql
  • .srf
  • .srt
  • .svg
  • .swf
  • .tar
  • .tbk
  • .tex
  • .TGA
  • .tga
  • .tgz
  • .thd
  • .tif
  • .tiff
  • .tivo
  • .torrent
  • .tp
  • .ts
  • .tta
  • .ttf
  • .txt
  • .vob
  • .voc
  • .vp6
  • .vp7
  • .vsd
  • .w64
  • .wav
  • .wbmp
  • .webm
  • .webp
  • .wma
  • .wmf
  • .wmv
  • .woff
  • .wpd
  • .wpl
  • .wps
  • .wtv
  • .x3f
  • .xa
  • .xcf
  • .xhtml
  • .xla
  • .xlam
  • .xls
  • .xlsx
  • .xm
  • .xmp
  • .xpi
  • .zip

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

  • .lsoc
  • un-lock

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

  • Program Files
  • ProgramData
  • Windows
  • PerfLogs
  • recovery
  • Recycle
  • $

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

  • .lsoc

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

  • %Public%\Windows\Ui\un-lock your files.html → file attribute set to HIDDEN | SYSTEM
  • %User Startup%\un-lock your files.html
  • %Desktop%\un-lock your files.html
  • %Start Menu%\un-lock your files.html
  • {Encrypted Drive}:\un-lock your files.html

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

19.200.04

FIRST VSAPI PATTERN DATE:

06 Mar 2024

VSAPI OPR PATTERN File:

19.201.00

VSAPI OPR PATTERN Date:

07 Mar 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:

    ADW.Win32.TRX.XXPE50FFF078

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 this file

[ 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.  
  • %User Temp%\{6 Random Characters}.bat
  • %Public%\Windows\Ui\un-lock your files.html
  • %User Startup%\un-lock your files.html
  • %Desktop%\un-lock your files.html
  • %Start Menu%\un-lock your files.html
  • {Encrypted Drive}:\un-lock your files.html

Step 5

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.  
  • %Public%\Windows\Ui

Step 6

Scan your computer with your Trend Micro product to delete files detected as Ransom.MSIL.SMINAJ.THCOFBD. 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:


Did this description help? Tell us how we did.