TROJ_DLDR.SET

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.

It deletes itself after execution.

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.

Autostart Technique

This Trojan registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\explorer\
Browser Helper Objects\{2D454237-7A38-48FD-B96B-017875822CB8}

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CLASSES_ROOT\CLSID\{2D454237-7A38-48FD-B96B-017875822CB8}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{2D454237-7A38-48FD-B96B-017875822CB8}\InProcServer32

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{2D454237-7A38-48FD-B96B-017875822CB8}\InProcServer32
ThreadingModel = "Apartment"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = "0"

Dropping Routine

This Trojan drops the following files:

• %Application Data%\htp.txt
• %Application Data%\mod.txt
• %Application Data%\hwwodqex.txt
• %Application Data%\ms.txt
• %Application Data%\msmsgs.cpl
• %Application Data%\wXP_F0BDFF95.txt
• %Application Data%\tcefni.dat
• %User Temp%\OUT_F0BDFF95_2.OUT

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.. %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.)

Other Details

This Trojan deletes itself after execution.

This report is generated via an automated analysis system.