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Ransom.Win32.LOCKBIT.YEBGW

August 16, 2021
 Analysis by: Bren Matthew Ebriega
 ALIASES:

Ransom:Win32/Lockbit.AA!MTB (MICROSOFT); W32/Lockbit.C2F8!tr.ransom (FORTINET)

 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


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:

883,200 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

23 Jul 2021

Payload:

Disables services, Displays message/message boxes, 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 the following files:

  • %User Temp%\{4 Hex 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
  • %System%\mshta.exe %Desktop%\LockBit_Ransomware.hta {1E460BD7-F1C3-4B2E-88BF-4E770A288AF5}{1E460BD7-F1C3-4B2E-88BF-4E770A288AF5}
  • %System%\cmd.exe /C ping 127.0.0.7 -n 3 > Nul & fsutil file setZeroData offset=0 length=524288 "{Malware Filepath}\{Malware Filename}" & Del /f /q "{Malware Filepath}\{Malware Filename}"

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

  • {D028A5BF-D028-A31F-9BF8-DBCBCB5CDB55}

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
{F068DCBF-2828-A337-9BF8-9BCB3D5CBF55} = {Malware Filepath}\{Malware Filename}.exe

Other System Modifications

This Ransomware adds the following registry entries:

HKEY_CURRENT_USER\Software\7D68A5BF281FF8
Private = {Hex Values}

HKEY_CURRENT_USER\Software\7D68A5BF281FF8
Public = {Hex Values}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
.lockbit
(Default) = Lockbit

HKEY_CLASSES_ROOT\Lockbit
(Default) = Lockbit Class

HKEY_CLASSES_ROOT\Lockbit\DefaultIcon
(Default) = %System%\{random}.ico

HKEY_CLASSES_ROOT\Lockbit\shell\
Open\Command
(Default) = %System%\mshta.exe %Desktop%\LockBit_Ransomware.hta

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

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %User Temp%\{4 Hex Characters}.tmp.bmp

HKEY_CURRENT_USER\Control Panel\Desktop
WallpaperStyle = 2

HKEY_CURRENT_USER\Control Panel\Desktop
TileWallpaper = 0

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

Process Termination

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

  • 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
  • MSExchange$
  • msftesql-Exchange
  • msmdsrv
  • MSSQL
  • MSSQL$
  • MSSQL$KAV_CS_ADMIN_KIT
  • MSSQL$MICROSOFT##SSEE
  • MSSQL$MICROSOFT##WID
  • MSSQL$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$VEEAMSQL2012
  • sqlbrowser
  • SQLBrowser
  • Sqlservr
  • SQLWriter
  • stc_raw_agent
  • svc$
  • tomcat6
  • veeam
  • VeeamDeploymentService
  • VeeamNFSSvc
  • VeeamTransportSvc
  • vmware-converter
  • vmware-usbarbitator64
  • VSNAPVSS
  • vss
  • wrapper
  • WSBExchange
  • YooBackup
  • YooIT
  • zhudongfangyu

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

  • 360doctor.exe
  • 360se.exe
  • acwebbrowser.exe
  • ADExplorer.exe
  • ADExplorer64.exe
  • ADExplorer64a.exe
  • Adobe CEF.exe
  • Adobe Desktop Service.exe
  • AdobeCollabSync.exe
  • AdobeIPCBroker.exe
  • agntsvc.exe
  • AutodeskDesktopApp.exe
  • Autoruns.exe
  • Autoruns64.exe
  • Autoruns64a.exe
  • Autorunsc.exe
  • Autorunsc64.exe
  • Autorunsc64a.exe
  • avz.exe
  • axlbridge.exe
  • bedbh.exe
  • benetns.exe
  • bengien.exe
  • beserver.exe
  • BrCcUxSys.exe
  • BrCtrlCntr.exe
  • CagService.exe
  • CoreSync.exe
  • Creative Cloud.exe
  • Culture.exe
  • dbeng50.exe
  • dbsnmp.exe
  • Defwatch.exe
  • DellSystemDetect.exe
  • dumpcap.exe
  • encsvc.exe
  • EnterpriseClient.exe
  • excel.exe
  • fbguard.exe
  • fbserver.exe
  • fdhost.exe
  • fdlauncher.exe
  • GDscan.exe
  • GlassWire.exe
  • GWCtlSrv.exe
  • Helper.exe
  • httpd.exe
  • infopath.exe
  • InputPersonalization.exe
  • isqlplussvc.exe
  • j0gnjko1.exe
  • java.exe
  • koaly-exp-engine-service.exe
  • msaccess.exe
  • MsDtSrvr.exe
  • mspub.exe
  • mydesktopqos.exe
  • mydesktopservice.exe
  • mysqld.exe
  • node.exe
  • notepad.exe
  • notepad++.exe
  • ocautoupds.exe
  • ocomm.exe
  • ocssd.exe
  • onenote.exe
  • ONENOTEM.exe
  • oracle.exe
  • outlook.exe
  • powerpnt.exe
  • ProcessHacker.exe
  • Procexp.exe
  • Procexp64.exe
  • procexp64a.exe
  • procmon.exe
  • procmon64.exe
  • procmon64a.exe
  • pvlsvr.exe
  • QBDBMgr.exe
  • QBDBMgrN.exe
  • QBIDPService.exe
  • qbupdate.exe
  • QBW32.exe
  • Raccine.exe
  • Raccine_x86.exe
  • RaccineElevatedCfg.exe
  • RaccineSettings.exe
  • RAgui.exe
  • raw_agent_svc.exe
  • RdrCEF.exe
  • RTVscan.exe
  • sam.exe
  • Simply.SystemTrayIcon.exe
  • SimplyConnectionManager.exe
  • sqbcoreservice.exe
  • sqlbrowser.exe
  • sqlmangr.exe
  • Sqlservr.exe
  • Ssms.exe
  • steam.exe
  • supervise.exe
  • sync-taskbar.exe
  • synctime.exe
  • sync-worker.exe
  • Sysmon.exe
  • Sysmon64.exe
  • SystemExplorer.exe
  • SystemExplorerService.exe
  • SystemExplorerService64.exe
  • tbirdconfig.exe
  • tcpview.exe
  • tcpview64.exe
  • tcpview64a.exe
  • tdsskiller.exe
  • TeamViewer.exe
  • TeamViewer_Service.exe
  • thebat.exe
  • thunderbird.exe
  • TitanV.exe
  • tomcat6.exe
  • Totalcmd.exe
  • Totalcmd64.exe
  • tv_w32.exe
  • tv_x64.exe
  • VeeamDeploymentSvc.exe
  • visio.exe
  • vsnapvss.exe
  • vxmon.exe
  • wdswfsafe.exe
  • winword.exe
  • WireShark.exe
  • wordpad.exe
  • wsa_service.exe
  • wxServer.exe
  • wxServerView.exe
  • xfssvccon.exe
  • ZhuDongFangYu.exe

Other Details

This Ransomware adds the following registry keys:

HKEY_CURRENT_USER\Software\7D68A5BF281FF8

It does the following:

  • It has the capability to print the ransom note in infected machines.
  • It encrypts files found in the following drive types:
    • Fixed drive
    • Removable drive
    • Network drive
    • RAM Disks

It accepts the following parameters:

  • {File Name or File Path to Encrypt} - if unspecified, the malware will infect all files except for the avoided ones.

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 with the following strings in their file path:

  • $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 renames encrypted files using the following names:

  • {Original Filename}.{Original File Extension}.lockbit

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

  • %Desktop%\Lockbit_Ransomware.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
  • .apk
  • .app
  • .bat
  • .bin
  • .cmd
  • .com
  • .cpl
  • .cur
  • .diagcab
  • .diagcgf
  • .diagpkg
  • .dll
  • .dmg
  • .dmp
  • .drv
  • .drv
  • .exe
  • .fnt
  • .fon
  • .gadget
  • .hlp
  • .hlp
  • .hta
  • .icns
  • .ico
  • .ics
  • .idx
  • .ini
  • .ipa
  • .iso
  • .key
  • .lnk
  • .lock
  • .lockbit
  • .mod
  • .mp3
  • .mp4
  • .mpa
  • .msc
  • .msi
  • .msstyles
  • .msp
  • .msu
  • .msu
  • .nls
  • .ocx
  • .otf
  • .part
  • .pif
  • .prf
  • .rdp
  • .reg
  • .rom
  • .rtp
  • .sfcache
  • .shs
  • .spl
  • .sys
  • .theme
  • .tmp
  • .ttf
  • .wad
  • .wav
  • .wma
  • .woff
  • .wpx
  • .xex

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

16.860.08

FIRST VSAPI PATTERN DATE:

23 Jul 2021

VSAPI OPR PATTERN File:

16.861.00

VSAPI OPR PATTERN Date:

24 Jul 2021

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.XXPE50FFF046

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

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\7D68A5BF281FF8
    • Private = {Hex Values}
  • In HKEY_CURRENT_USER\Software\7D68A5BF281FF8
    • Public = {Hex Values}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\.lockbit
    • (Default) = Lockbit
  • In HKEY_CLASSES_ROOT\Lockbit
    • (Default) = Lockbit Class
  • In HKEY_CLASSES_ROOT\Lockbit\DefaultIcon
    • (Default) = %System%\{random}.ico
  • In HKEY_CLASSES_ROOT\Lockbit\shell\Open\Command
    • (Default) = %System%\mshta.exe %Desktop%\LockBit_Ransomware.hta

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\
    • 7D68A5BF281FF8

Step 6

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%\{4 Hex Characters}.tmp.bmp
  • %Desktop%\Lockbit_Ransomware.hta
  • {Encrypted Directory}\Restore-My-Files.txt

Step 7

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

Step 8

Reset your Desktop properties

[ Learn More ]

Step 9

Restore encrypted files from backup.


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