TROJ_DROPPER.FYV

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\Wilbert
• %User Profile%\LOCALS~1
• %User Temp%\nsx3.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:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} 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 System Modifications

This Trojan deletes the following files:

• %User Temp%\nsh1.tmp
• %User Temp%\nsx3.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.)

It adds the following registry keys:

HKEY_CURRENT_USER\Software\AppDataLow\
Software\{D02E7CE6-D6B9-33FE-603F-F855EC4CABE5}

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
wgjngbonphwjwni

It adds the following registry entries:

HKEY_CURRENT_USER\Software\AppDataLow\
Software\{D02E7CE6-D6B9-33FE-603F-F855EC4CABE5}
aff_id = "clickbuster"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
wgjngbonphwjwni
DisplayName = "Tagging System Clickbuster."

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
wgjngbonphwjwni
UninstallString = "{random characters}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
wgjngbonphwjwni
NoModify = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
wgjngbonphwjwni
NoRepair = "0"

Dropping Routine

This Trojan drops the following files:

• %User Temp%\nsx2.tmp
• %User Temp%\nsx3.tmp\System.dll
• %User Temp%\nsb4.tmp.dll
• %System%\wgjngbonphwjwni.exe
• %User Temp%\ap1B1DB.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.. %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

Other Details

This Trojan connects to the following possibly malicious URL:

• http://{BLOCKED}uster.net/bc/nsi_install.php?{random characters}

This report is generated via an automated analysis system.