Ransom.Win32.MATRIX.SMTH

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.

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 copies of itself into the affected system:

• {Malware file path}\{Random characters}.exe

It drops the following files:

• {Malware file path}\{Random characters}.bat
• {Malware file path}\ALL_dmpfl.fldp
• {Malware file path}\log.txt
• %Application Data%\{Random characters}.bmp
• %Application Data%\{Random characters}.bat
• %Application Data%\{Random characters}.vbs

(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 processes:

• "%System%\cmd.exe" /C copy /V /Y "{Malware file path and name}" "{Malware file path}\{Random characters}.exe"
• "{Malware file path}\{Random characters}.exe" -n
• "%System%\cmd.exe" /C reg add "HKCU\Control Panel\Desktop" /v Wallpaper /t REG_SZ /d "%Application Data%\{Random characters}.bmp" /f & reg add "HKCU\Control Panel\Desktop" /v WallpaperStyle /t REG_SZ /d "0" /f & reg add "HKCU\Control Panel\Desktop" /v TileWallpaper /t REG_SZ /d "0" /f
• "%System%\cmd.exe" /C wscript //B //Nologo "%Application Data%\{Random characters}.vbs";
• "%System%\cmd.exe" /C schtasks /Create /tn DSHCA /tr "%Application Data%\{Random characters}.bat" /sc minute /mo 5 /RL HIGHEST /F
• "%System%\cmd.exe" /C schtasks /Run /I /tn DSHCA
• cmd /c ""{Malware file path}\{Random characters}.bat" "{File to be encrypted}"
• cacls "{File to be encrypted}" /E /G {Computer name}:F /C
• takeown /F "{File to be encrypted}"
• %System%\cmd.exe /c {Random characters}.exe -accepteula "{File to be encrypted}" -nobanner
• vssadmin Delete Shadows /All /Quiet
• wmic SHADOWCOPY DELETE

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %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).)

Other System Modifications

This Ransomware modifies the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %Application Data%\{Random characters}.bmp

HKEY_CURRENT_USER\Control Panel\Desktop
WallpaperStyle = 0

HKEY_CURRENT_USER\Control Panel\Desktop
TileWallpaper = 0

HKEY_CURRENT_USER\Software\Sysinternals\
Handle
EulaAccepted = 1

Other Details

This Ransomware adds the following scheduled tasks:

• Name: DSHCA
  Path: %Application Data%\{Random characters}.bat

(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).)

Ransomware Routine

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

• .[{BLOCKED}ans333@criptext.com].{Random characters}.MKES

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

• {Encrypted file path}\#MKES_INFO#.rtf