Ransom.Win64.LOCKBIT.C

April 24, 2023
 Analysis by: Rojan Dela Cruz
 ALIASES:

Trojan.Win64.Krypt (IKARUS),

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

  TECHNICAL DETAILS

File Size:

251,392 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

29 Mar 2023

Payload:

Encrypts files, Displays message/message boxes

Installation

This Ransomware adds the following processes:

  • cmd.exe /c C:WindowsSystem32wbemWMIC.exe shadowcopy where "ID='%s'" delete → used to delete shadow copies

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

  • Mutex Name: hsfjuukjzloqu28oajh727190

Other Details

This Ransomware does the following:

  • It also encrypts database related file extensions:
    • .4dd
    • .4dl
    • .accdb
    • .accdc
    • .accde
    • .accdr
    • .accdt
    • .accft
    • .adb
    • .ade
    • .adf
    • .adp
    • .arc
    • .ora
    • .alf
    • .ask
    • .btr
    • .bdf
    • .cat
    • .cdb
    • .ckp
    • .cma
    • .cpd
    • .dacpac
    • .dad
    • .dadiagrams
    • .daschema
    • .db
    • .db-shm
    • .db-wal
    • .db3
    • .dbc
    • .dbf
    • .dbs
    • .dbt
    • .dbv
    • .dbx
    • .dcb
    • .dct
    • .dcx
    • .ddl
    • .dlis
    • .dp1
    • .dqy
    • .dsk
    • .dsn
    • .dtsx
    • .dxl
    • .eco
    • .ecx
    • .edb
    • .epim
    • .exb
    • .fcd
    • .fdb
    • .fic
    • .fmp
    • .fmp12
    • .fmps1
    • .fol
    • .fp3
    • .fp4
    • .fp5
    • .fp7
    • .fpt
    • .frm
    • .gdb
    • grbd
    • .gwi
    • .hdb
    • .his
    • .ib
    • .idb
    • .ihx
    • .itdb
    • .itw
    • .kexi
    • .kexic
    • .kexis
    • .lwx
    • .jet
    • .jtx
    • .lgc
    • .kdb
    • .maf
    • .maq
    • .mar
    • .mas
    • .mav
    • .mdb
    • .mdf
    • .mpd
    • .mrg
    • .mud
    • .mwb
    • .myd
    • .ndf
    • .nnt
    • .nrmlib
    • .ns2
    • .ns3
    • .ns4
    • .nsf
    • .nv
    • .nv2
    • .nwdb
    • .nyf
    • .odb
    • .oqy
    • .orx
    • .owc
    • .p96
    • .p97
    • .pan
    • .pdb
    • .pdm
    • .pnz
    • .qry
    • .qvd
    • .rbf
    • .rctd
    • .rod
    • .rodx
    • .rpd
    • .rsd
    • .sbf
    • .scx
    • .sdb
    • .sdc
    • .sas7bdat
    • .sbf
    • .scx
    • .sis
    • .spq
    • .sdb
    • .sdc
    • .sdf
    • .sql
    • .sqlite
    • .sqlite3
    • .sqlitedb
    • .te
    • .temx
    • .tmd
    • .tps
    • .trc
    • .trm
    • .udb
    • .udl
    • .usr
    • .v12
    • .vis
    • .vpd
    • .vvv
    • .wdb
    • .wmdb
    • .wrk
    • .xdb
    • .xmlff
    • .abcddb
    • .xld
    • .abs
    • .abx
    • .accdw
    • .adn
    • .db2
    • .fm5
    • .hjt
    • .icg
    • .icr
    • .kdb
    • .lut
    • .maw
    • .mdn
    • .mdt
  • It also encrypts disk image related files extensions:
    • .vdi
    • .vhd
    • .pvm
    • .vmx
    • .raw
    • .bin
    • .vsv
    • .iso
    • .vmdk
    • .vmem
    • .vmsn
    • .vmsd
    • .avhd
    • .vmrs
    • .vhdx
    • .avdx
    • .vmcx
    • .nvram
    • .qcow2
    • .subvol
  • Checking if the network share starts with the IP address:
    • 172.
    • 192.168.
    • 10.
    • 169.
    It only encrypt files that are in the network share if it is in local network

It accepts the following parameters:

  • -log {file name} – create log output base on the file name that you enter to parameter
  • -size – {chunk mode}
  • -nomutex – it doesn’t create mutex
  • -m - delete all backups and encrypt all
  • -p - encrypt specific folder first before proceeding to other folders
  • -m -{local|net|backups}
    • local - delete backups and encrypt local drives
    • net - delete backups and encrypt network shares
    • backups - delete backups

Ransomware Routine

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

  • CONTI_LOG.txt
  • !!!-Restore-My-Files-!!!.txt

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

  • tmp
  • winnt
  • temp
  • thumb
  • $Recycle.Bin
  • $RECYCLE.BIN
  • System Volume Information
  • Boot
  • Windows
  • Trend Micro
  • perflogs

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

  • .6b226bbd

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

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

It avoids encrypting files with the following file extensions:

  • .6b226bbd
  • .exe
  • .dll
  • .lnk
  • .sys
  • .msi
  • .bat

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

18.350.02

FIRST VSAPI PATTERN DATE:

29 Mar 2023

VSAPI OPR PATTERN File:

18.351.00

VSAPI OPR PATTERN Date:

30 Mar 2023

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:

    • Ransom.Win32.TRX.XXPE50FFF067

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 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}\!!!-Restore-My-Files-!!!.txt

Step 5

Scan your computer with your Trend Micro product to delete files detected as Ransom.Win64.LOCKBIT.C. 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 6

Restore encrypted files from backup.


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