Ransom.Win32.MAZE.YAAH-A

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%\dump001.tmp
• %User Temp%\111.bmp

(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.. %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:

• "C:\{Random characters}\{Random characters}\{Random characters}\..\..\..\Windows\{Random characters}\{Random characters}\..\..\system32\{Random characters}\{Random characters}\{Random characters}\..\..\..\wbem\{Random characters}\{Random characters}\..\..\wmic.exe" shadowcopy delete

Other System Modifications

This Ransomware changes the desktop wallpaper by modifying the following registry entries:

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = %User Temp%\111.bmp

Process Termination

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

• dumpcap.exe
• excel.exe
• fiddler.exe
• msaccess.exe
• mysqld-nt.exe
• outlook.exe
• pipanel.exe
• procexp64.exe
• procexp.exe
• procmon64.exe
• procmon.exe
• python.exe
• taskkill.exe
• visio.exe
• winword.exe -
• x32dbg.exe
• x64dbg.exe

Other Details

This Ransomware displays the following images:

It does the following:

• It uses Windows Text-to-Speech functionality to play the following message:
  • {Username}! Alert! {Username}! Alert! Dear {Username}, your files have been encrypted by Maze Ransomware! Attention! You need to buy decryptor in order to restore the files.

Ransomware Routine

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

• DECRYPT-FILES.txt
• autorun.inf
• boot.ini
• desktop.ini
• ntuser.dat
• iconcache.db
• bootsect.bak
• ntuser.dat.log
• thumbs.db
• Bootfont.bin

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

• :\Windows
• \Games\
• \Tor Browser\
• \ProgramData\
• \cache2\entries\
• \Low\Content.IE5\
• \User Data\Default\Cache\
• \All Users
• \IETldCache\
• \Local Settings\
• \AppData\Local
• \Program Files

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

• .{Random characters}

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

• {Encrypted directory}\DECRYPT-FILES.txt
  

It avoids encrypting files with the following file extensions:

• .lnk
• .exe
• .sys
• .dll