Ransom.Win64.WINTENZ.THDABBA

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 terminates itself if it detects it is being run in a virtual environment.

It encrypts files with specific file extensions. It encrypts files found in specific folders. 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 files:

• %User Startup%\winstrt10.exe - copy of itself
• %Public%\rstrt.bat - used to display ransom note
• %All Users Profile%\winfrce.bat - delete shadow copies
• %All Users Profile%\zwin.new

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 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.. %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit). )

It adds the following processes:

• vssadmin.exe Delete Shadows /All /Quiet
• vssadmin.exe Resize ShadowStorage /For=C: /On=C: /MaxSize=320MB
• start "" "%User Startup%\STARTOPEN_ote.html"
• powershell get-wmiobject win32_computersystem|flmodel - to check if running in a virtual environment
• powershell-VerbrunasStart-process (get.location).Drive.Name

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows 2003(32-bit), XP and 2000(32-bit), or C:\Users\{user name}\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit), 10(64-bit).)

Other Details

This Ransomware terminates itself if it detects it is being run in a virtual environment.

Ransomware Routine

This Ransomware encrypts files with the following extensions:

• pdf
• docx
• doc
• txt
• xls
• xlsx
• odt
• ods
• ppt
• pptx
• png
• jpg
• mp3
• mp4

It encrypts files found in the following folders:

• %Application Data%\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar\
• %User Profile%\Music\
• %User Profile%\Downloads\
• %User Profile%\Videos\
• %User Profile%\Pictures\
• %User Profile%\Documents\
• %Desktop%\

(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).. %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).. %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).)

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

• .wintenzz

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

• %User Startup%\STARTOPEN_ote.html
  
• %Desktop%\BUY_WINTENNZ.txt