TROJ_DLDR.SMIM

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:

• %System Root%\DOCUME~1
• %System Root%\DOCUME~1\ADMINI~1
• %User Profile%\LOCALS~1
• %User Temp%\nso3.tmp

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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.)

Other System Modifications

This Trojan deletes the following files:

• %User Temp%\nso1.tmp
• %User Temp%\nso3.tmp

(Note: %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.)

It deletes the following folders:

• %User Temp%\nso3.tmp\

(Note: %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.)

Dropping Routine

This Trojan drops the following files:

• %User Temp%\nso2.tmp
• %User Temp%\nso3.tmp\inetc.dll
• %User Temp%\guad_3731.exe
• %User Temp%\NewFu3731.exe
• %User Temp%\yule3731.exe

(Note: %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.)

Other Details

This Trojan connects to the following possibly malicious URL:

• http://downes.{BLOCKED}che.info/soft/guad_3731.exe
• http://downes.{BLOCKED}che.info/soft/NewFu3731.exe
• http://downes.{BLOCKED}che.info/soft/yule3731.exe

This report is generated via an automated analysis system.