RANSOM_SPORA.THEAH

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 modifies Internet Explorer security settings. This puts the affected computer at greater risk, as it allows malicious URLs to be accessed by the computer.

It encrypts files with specific file extensions. 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:

• %Application Data%\Xkj1VYCu

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

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

• Xkj1VYCu

Web Browser Home Page and Search Page Modification

This Ransomware modifies Internet Explorer zone settings.

Other Details

This Ransomware does the following:

• Execute the following command:
  • vssadmin.exe delete shadows /quiet /all
• Display the following ransom note(from the url {BLOCKED}.{BLOCKED}.19.190 ):

  

Ransomware Routine

This Ransomware encrypts files with the following extensions:

• .bak
• .sql
• .backup
• .7z
• .rar
• .zip
• .tiff
• .jpeg
• .jpg
• .accdb
• .sqlite
• .dbf
• .1cd
• .mdb
• .cd
• .cdr
• .dwg
• .psd
• .pptx
• .ppt
• .pdf
• .odt
• .rtf
• .docx
• .xlsx
• .doc
• .xls

It avoids encrypting files found in the following folders:

• windows
• program files
• program files (x86)
• games
• appdata

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

• {Encrypted File Directory}\HELP_Xkj1VYCu.html
• %User Startup%\HELP_Xkj1VYCu.html

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Documents and Settings\{user}\Start Menu\Programs\Startup on Windows 2000 and XP, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup on Windows Vista, 7, and 8.)