Ransom.Win32.LOCKBIT.YADLVT

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.

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:

• %ProgramData%\670IGylFT.ico → icon used for all encrypted files.
• %ProgramData%\670IGylFT.bmp → image used as Desktop wallpaper.

(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)

It 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\
.670IGylFT
{Default} = 670IGylFT

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
670IGylFT\DefaultIcon
{Default} = %ProgramData%\670IGylFT.ico

It modifies the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
WallPaper = %ProgramData%\670IGylFT.bmp

HKEY_CURRENT_USER\Control Panel\Desktop
WallpaperStyle = 10

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

• %ProgramData%\670IGylFT.bmp:
  

Process Termination

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

• 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

Other Details

This Ransomware adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes
.670IGylFT

HKEY_LOCAL_MACHINE\SOFTWARE\Classes
670IGylFT\DefaultIcon

It requires the following additional components to properly run:

• {Malware Path}\PP.bat → detected as Ransom.BAT.LOCKBIT.A

It does the following:

• It changes the encrypted file's icon to the following image:
  
• It encrypts fixed, removable and network shares.
• It uses WQL to delete volume shadow copies.
• It terminates if the machine has the following system language:
  • Arabic (Syria)
  • Armenian (Armenia)
  • Azerbaijani (Cyrillic Azerbaijan)
  • Azerbaijani (Latin Azerbaijan)
  • Belarusian (Belarus)
  • Georgian (Georgia)
  • Kazakh (Kazakhstan)
  • Kyrgyz (Kyrgyzstan)
  • Russian (Moldova)
  • Russian (Russia)
  • Tajik (Cyrillic Tajikistan)
  • Tatar (Russia)
  • Romanian (Moldova)
  • Turkmen (Turkmenistan)
  • Ukranian (Ukraine)
  • Uzbek (Cyrillic Uzbekistan)
  • Uzbek (Latin Uzbekistan)
• It deletes the following services if found running on the affected system:
  • EventLog
  • SecurityHealthService
  • Sense
  • sppsvc
  • vmicvss
  • vmvss
  • VSS
  • WdBoot
  • WdFilter
  • WdNisDrv
  • WdNisSvc
  • WinDefend
  • wscsvc
• It contains the following export functions which can be loaded using command line arguments:
  • del → function responsible for deleting itself.
  • gdel → function responsible for deleting group policy.
  • gmod → function responsible for updating group policy.
  • wdll → function responsible for installing the icon and changing the Desktop wallpaper.
  • gdll → function responsible for encrypting the infected system.
  • sdll → function responsible for restarting the system in safe mode.
  • pmod

It accepts the following parameters:

• -pass {32 Random Hex Values / Hash} → used as a key to properly execute its intended routine.

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
• 670IGylFT.README.txt

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

• .670IGylFT

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

• {Encrypted Directory}\670IGylFT.README.txt
• %Desktop%\670IGylFT.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
• .670IGylFT