Analysis by: Joshua Paul Ignacio

ALIASES:

Ransom:Win32/Lockbit.SA!MSR (MICROSOFT), HEUR:Trojan.Win32.DelShad.vho (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 executes then deletes itself afterward.

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

  TECHNICAL DETAILS

File Size: 149,504 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 03 Dec 2020
Payload: Drops files, Displays graphics/image, Encrypts files, Displays message/message boxes

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 the following files:

  • %User Temp%\{Random Characters}.tmp.bmp → used as wallpaper

(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:

  • "%System%\cmd.exe" /c vssadmin delete shadows /all /quiet & wmic shadowcopy delete & bcdedit /set {default} bootstatuspolicy ignoreallfailures & bcdedit /set {default} recoveryenabled no & wbadmin delete catalog -quiet
  • "%System%\mshta.exe" "%Desktop%\LockBit-note.hta"
  • "%System%\cmd.exe" /C ping 127.0.0.7 -n 3 > Nul & fsutil file setZeroData offset=0 length=524288 "{Malware Path}\{Malware Filename}.exe" & Del /f /q "{Malware Path}\{Malware Filename}.exe"

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %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 executes then deletes itself afterward.

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

  • Global\{BEF590BE-11A6-442A-A85B-656C1081E04C}

Autostart Technique

This Ransomware adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
XO1XADpO01 = "{Malware Path}\{Malware Filename}.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{GUID} = %Desktop%\LockBit-note.hta

Other System Modifications

This Ransomware adds the following registry entries:

HKEY_CURRENT_USER\Software\LockBit
full = {Hex Values}

HKEY_CURRENT_USER\Software\LockBit
Public = {Hex Values}

It changes the desktop wallpaper by modifying the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
WallpaperStyle = 2

HKEY_CURRENT_USER\Control Panel\Desktop
TileWallpaper = 0

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %User Temp%\{Random Characters}.tmp.bmp

It sets the system's desktop wallpaper to the following image:

Process Termination

This Ransomware terminates processes or services that contain any of the following strings if found running in the affected system's memory:

  • AcronisAgent
  • AcrSch2Svc
  • ARSM
  • backup
  • BackupExecAgentAccelerator
  • BackupExecAgentBrowser
  • BackupExecDiveciMediaService
  • BackupExecJobEngine
  • BackupExecManagementService
  • BackupExecRPCService
  • BackupExecVSSProvider
  • bedbg
  • CAARCUpdateSvc
  • CASAD2DWebSvc
  • ccEvtMgr
  • ccSetMgr
  • Culserver
  • dbeng8
  • dbsrv12
  • DefWatch
  • FishbowlMySQL
  • Intuit.QuickBooks.FCS
  • memtas
  • mepocs
  • MSExchange
  • msftesql-Exchange
  • msmdsrv
  • MSSQL
  • MSSQL$
  • MSSQL$KAV_CS_ADMIN_KIT
  • MSSQL$MICROSOFT##SSEE
  • MSSQL$MICROSOFT##WID
  • MSSQL$SBSMONITORING
  • MSSQL$SHAREPOINT
  • MSSQL$VEEAMSQL2012
  • MSSQLFDLauncher$SBSMONITORING
  • MSSQLFDLauncher$SHAREPOINT
  • MSSQLServerADHelper100
  • MVArmor.MVarmor64
  • MySQL57
  • PDVFSService
  • QBCFMonitorService
  • QBFCService
  • QBIDPService
  • QBVSS
  • RTVscan
  • SavRoam
  • sophos
  • sql
  • sqladhlp
  • SQLADHLP
  • sqlagent
  • SQLAgent$KAV_CS_ADMIN_KIT
  • SQLAgent$SBSMONITORING
  • SQLAgent$SHAREPOINT
  • SQLAgent$VEEAMSQL2012
  • sqlbrowser
  • SQLBrowser
  • Sqlservr
  • sqlwriter
  • SQLWriter
  • stc_raw_agent
  • svc$
  • tomcat6
  • veeam
  • VeeamDeploymentService
  • VeeamNFSSvc
  • VeeamTransportSvc
  • vmware-converter
  • vmware-usbarbitator64
  • VSNAPVSS
  • vss
  • wrapper
  • WSBExchange
  • YooBackup
  • YooIT
  • zhudongfangyu

Other Details

This Ransomware adds the following registry keys:

HKEY_CURRENT_USER\Software\LockBit

It does the following:

  • It checks for the computer's language and terminates itself if any the following language is detected:
    • Armenian
    • Azerbaijani (Cyrillic)
    • Azerbaijani (Latin)
    • Belarusian
    • Georgian
    • Kazakh
    • Kyrgyz
    • Russian
    • Russian (Maldova)
    • Taijik (Cyrillic)
    • Turkmen
    • Turkmen
    • Ukrainian
    • Uzbek (Cyrillic)
    • Uzbek (Latin)

Ransomware Routine

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

  • autorun.inf
  • bootsect.bak
  • iconcache.db
  • ntldr
  • ntuser.dat.log
  • Restore-My-Files.txt
  • thumbs.db

It avoids encrypting files found in the following folders:

  • $recycle.bin
  • $windows.~bt
  • $windows.~ws
  • All users
  • appdata
  • application data
  • boot
  • common files
  • google
  • intel
  • Internet Explorer
  • Microsoft
  • microsoft shared
  • Microsoft.NET
  • mozilla
  • Msbuild
  • msocache
  • opera
  • perflogs
  • system volume information
  • tor browser
  • windows
  • Windows Journal
  • Windows nt
  • windows.old

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

  • %Desktop%\LockBit-note.hta

It leaves text files that serve as ransom notes containing the following text:

  • {Encrypted Directory}\Restore-My-Files.txt

It avoids encrypting files with the following file extensions:

  • .386
  • .adv
  • .ani
  • .bat
  • .bin
  • .cmd
  • .com
  • .cpl
  • .diagcab
  • .diagcfg
  • .diagpkg
  • .dll
  • .drv
  • .exe
  • .hlp
  • .hta
  • .icns
  • .ico
  • .ics
  • .idx
  • .ini
  • .key
  • .lnk
  • .lock
  • .lockbit
  • .mod
  • .mp3
  • .mpa
  • .msc
  • .msi
  • .msp
  • .msstyles
  • .msu
  • .nls
  • .ocx
  • .prf
  • .ps1
  • .rdp
  • .reg
  • .rom
  • .rtp
  • .shs
  • .spl
  • .sys
  • .theme
  • .wpx

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 16.392.03
FIRST VSAPI PATTERN DATE: 04 Dec 2020
VSAPI OPR PATTERN File: 16.393.00
VSAPI OPR PATTERN Date: 05 Dec 2020

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.XXPE50FFF038

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 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\Run
    • XO1XADpO01 = "{Malware Path}\{Malware Filename}.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • {GUID} = %Desktop%\LockBit-note.hta
  • In HKEY_CURRENT_USER\Software\LockBit
    • full = {Hex Values}
  • In HKEY_CURRENT_USER\Software\LockBit
    • Public = {Hex Values}

Step 6

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.

  • HKEY_CURRENT_USER\Software\LockBit

Step 7

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.
  • %User Temp%\{Random Characters}.tmp.bmp
  • {Encrypted Directory}\Restore-My-Files.txt
  • %Desktop%\LockBit-note.hta

Step 8

Reset your Desktop properties

[ Learn More ]

Step 9

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Ransom.Win32.LOCKBIT.J. 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 10

Restore encrypted files from backup.


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