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Ransom.MSIL.LUCKNITE.A

January 10, 2023
 Analysis by: Jayvee Mark Villaroman
 ALIASES:

MSIL/Filecoder.F9C3!tr.ransom (FORTINET), Ransom:MSIL/FileCoder.AD!MTB (MICROSOFT)

 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 uses file names similar to those of legitimate applications to trick a user into thinking they are legitimate.

It encrypts files found in specific folders. It drops files as ransom note.

  TECHNICAL DETAILS

File Size:

23,552 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

16 Dec 2022

Payload:

Displays message/message boxes, Drops files, Encrypts files

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:

  • {All affected directories}\README.txt
  • %Application Data%\svchost.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming 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:

  • bc1qw0ll8p9m8uezhqhyd7z459ajrk722yn8c5j4fg
  • 17CqMQFeuB3NTzJ2X28tfRmWaPyPQgvoHV

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Microsoft Store = {ransomware location}

It drops the following file(s) in the Windows Startup folder to enable its automatic execution at every system startup:

  • svchost.url ← links to ransomware location

Other System Modifications

This Ransomware uses the following commands to delete built-in operating system data to prevent data recovery:

  • wbadmin delete catalog -quiet
  • vssadmin delete shadows /all /quiet & wmic shadowcopy delete
  • bcdedit /set {default} bootstatuspolicy ignoreallfailures & bcdedit /set {default} recoveryenabled no

Propagation

This Ransomware drops the following copy of itself in all physical and removable drives:

  • surprise.exe (except C: drive)

Other Details

This Ransomware encrypts files with the following extensions:

  • .1cd
  • .3ds
  • .3fr
  • .3g2
  • .3gp
  • .7z
  • .7zip
  • .accda
  • .accdb
  • .accdc
  • .accde
  • .accdr
  • .accdt
  • .accdw
  • .ace
  • .adp
  • .ai
  • .ai3
  • .ai4
  • .ai5
  • .ai6
  • .ai7
  • .ai8
  • .amv
  • .apk
  • .arj
  • .arw
  • .ascx
  • .asm
  • .asmx
  • .asp
  • .aspx
  • .avi
  • .avs
  • .backup
  • .bak
  • .bay
  • .bin
  • .bk
  • .blob
  • .bmp
  • .bz2
  • .cab
  • .cer
  • .cfm
  • .config
  • .contact
  • .core
  • .cpp
  • .crt
  • .cs
  • .css
  • .csv
  • .cub
  • .cvs
  • .dae
  • .dat
  • .db
  • .dbf
  • .dbx
  • .dc3
  • .dcm
  • .dcr
  • .dib
  • .dic
  • .dif
  • .divx
  • .djvu
  • .dmg
  • .doc
  • .docm
  • .docx
  • .dot
  • .dotx
  • .dwg
  • .dwt
  • .epsp
  • .exif
  • .exr
  • .f4v
  • .flv
  • .geo
  • .gif
  • .gz
  • .gzip
  • .htm
  • .html
  • .ibank
  • .ico
  • .iff
  • .inc
  • .indd
  • .ini
  • .iso
  • .jar
  • .java
  • .jpe
  • .jpeg
  • .jpg
  • .js
  • .json
  • .jsp
  • .key
  • .kmz
  • .kwm
  • .lnk
  • .log
  • .lzh
  • .m1v
  • .m4a
  • .m4p
  • .m4v
  • .max
  • .mda
  • .mdb
  • .mde
  • .mdf
  • .mdw
  • .mht
  • .mhtml
  • .mka
  • .mkv
  • .mov
  • .mp3
  • .mp4
  • .mpeg
  • .mpg
  • .mpv
  • .msg
  • .myi
  • .nef
  • .obj
  • .odc
  • .odm
  • .odp
  • .ods
  • .odt
  • .oft
  • .onepkg
  • .onetoc2
  • .opt
  • .oqy
  • .orf
  • .p7b
  • .p7c
  • .p12
  • .pam
  • .pas
  • .pdb
  • .pdf
  • .pfx
  • .php
  • .pict
  • .pl
  • .pls
  • .png
  • .pot
  • .potm
  • .potx
  • .ppam
  • .pps
  • .ppsm
  • .ppt
  • .pptm
  • .pptx
  • .ps
  • .psb
  • .psd
  • .pst
  • .py
  • .r3d
  • .rar
  • .raw
  • .rb
  • .rgbe
  • .rss
  • .rtf
  • .safe
  • .settings
  • .sie
  • .slk
  • .sln
  • .sql
  • .stm
  • .sum
  • .svg
  • .svgz
  • .swf
  • .swift
  • .tab
  • .tar
  • .tar.gz
  • .tbi
  • .tif
  • .torrent
  • .txt
  • .vb
  • .vbs
  • .vdi
  • .vmdk
  • .vob
  • .vss
  • .wallet
  • .wav
  • .webm
  • .wma
  • .wmv
  • .wpd
  • .wps
  • .xla
  • .xlam
  • .xlk
  • .xlm
  • .xls
  • .xlsb
  • .xlsm
  • .xlsx
  • .xlt
  • .xltm
  • .xltx
  • .xlw
  • .xml
  • .xps
  • .xsd
  • .xsf
  • .xsl
  • .xz
  • .zip

It uses file names similar to those of legitimate applications to trick a user into thinking they are legitimate.

It does the following:

  • This ransomware uses different encryption methods to target files depending on its file size:
    • If file size is less than 2,117,152 bytes:
      • It uses AES encryption to encrypt the file
    • If file size is more than 200,000,000 bytes:
      • It uses a randomly generated Base64 string, then it appends the generated 4-character string to the file name.
    • If file size is more than 2,117,152 bytes and less than 200,000,000 bytes:
      • It generates a Base64 string from a random UTF-8 encoded bytes of length equal to a quarter of the file size and writes the string to the file. It appends the generated 4-character string to the file name.

Ransomware Routine

This Ransomware encrypts files found in the following folders:

  • %Desktop%
  • %User Profile%\Links
  • %User Profile%\Contacts
  • %User Profile%\Documents
  • %User Profile%\Downloads
  • %User Profile%\Pictures
  • %User Profile%\Music
  • %User Profile%\OneDrive
  • %User Profile%\Saved Games
  • %Favorites%
  • %User Profile%\Searches
  • %User Profile%\Videos
  • %Application Data%
  • %Public%\Documents
  • %Public%\Pictures
  • %Public%\Music
  • %Public%\Videos
  • %Public%\Desktop

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

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

  • .lucknite
  • README.txt

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

  • .lucknite

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

  • README.txt

  SOLUTION

Minimum Scan Engine:

9.800

FIRST VSAPI PATTERN FILE:

18.186.02

FIRST VSAPI PATTERN DATE:

10 Jan 2023

VSAPI OPR PATTERN File:

18.187.00

VSAPI OPR PATTERN Date:

11 Jan 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:

     
    • TROJ.Win32.TRX.XXPE50FFF063

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Microsoft Store = {ransomware location}

Step 5

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.
  • {All drives except C}\surprise.exe
  • %User Startup%\svchost.url
  • {All affected directories}\README.txt
  • %Application Data%\svchost.exe

Step 6

Enabling Volume Shadow Service

  1. Run the command prompt (cmd.exe) as administrator.
  2. Enable Volume Shadow Service by typing the following command:
    net start vss

Step 7

Enabling Windows Error Recovery

  1. Run the command prompt (cmd.exe) as administrator.
  2. Enable Windows Error Recovery Screen on Startup by typing the following command:
    bcdedit /set {default} bootstatuspolicy displayallfailures

Step 8

Restore files from backup Only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on your computer again.

Step 9

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


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