TROJ_DROPPER.WQH

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 may be manually installed by a user.

It uses common file icons to trick a user into thinking that the files are legitimate.

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.

It may be manually installed by a user.

Installation

This Trojan drops a copy of itself in the following folders using different file names:

• %Application Data%\{random characters}.exe

(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.)

It uses common file icons to trick a user into thinking that the files are legitimate.

It injects itself into the following processes as part of its memory residency routine:

• svchost.exe

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random characters} = %Application Data%\{random characters}.exe

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software\{random key}
{random characters} = {random value}

HKEY_CURRENT_USER\Software\{random key}
{random characters} = 1

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

• http://{BLOCKED}levelll1931.ru/forum/get/f3.dll.crp
• http://{BLOCKED}duzbekis75.ru/forum/index.php
• http://www.{BLOCKED}asa.com/fincascarema/svc.dll