TROJ_MEDFOS.JRR

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Arrival Details

This Trojan 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 Trojan creates the following folders:

• %User Profile%\Application Data\Java

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Other System Modifications

This Trojan deletes the following files:

• %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.1732.91890
• %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.1732.91937
• %User Profile%\v2.0.50727.42\security.config.cch.1732.93312
• %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.1876.125953
• %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.1876.125953
• %User Profile%\v2.0.50727.42\security.config.cch.1876.126046

(Note: %Windows% is the Windows folder, which is usually C:\Windows.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"

(Note: The default value data of the said registry entry is 2.)

Dropping Routine

This Trojan drops the following files:

• %User Profile%\Application Data\iexplorer.exe
• %User Profile%\Application Data\MLKjT.vbs
• %User Temp%\TT Copy.jpg

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

This report is generated via an automated analysis system.