TROJ_INJPLORE.A

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 drops the following copies of itself into the affected system:

• %User Startup%\uqchowhg.exe
• %Program Files%\{characters}uqchowhg.exe\uqchowhg.exe

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.. %Program Files% is the default Program Files folder, usually C:\Program Files.)

It drops the following non-malicious file:

• %Program Files%\Internet Explorer\dmlconf.dat

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

Autostart Technique

This Trojan modifies the following registry entry(ies) to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "%System%\userinit.exe,,%Program Files%\{characters}uqchowhg.exe\uqchowhg.exe"

(Note: The default value data of the said registry entry is %System%\userinit.exe,.)

Other System Modifications

This Trojan creates the following registry entry(ies) to bypass Windows Firewall:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Program Files%\Internet Explorer\IEXPLORE.EXE = "%Program Files%\Internet Explorer\IEXPLORE.EXE:*:Enabled:Internet Explorer"