TROJ_FAKEAV.THEB

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 uses a convincing Graphical User Interface to make the users think that the software is legitimate.

It employs registry shell spawning by adding certain registry entries. This allows this malware to execute even when other applications are opened.

It connects to certain URLs. It may do this to remotely inform a malicious user of its installation. It may also do this to download possibly malicious files onto the computer, which puts the computer at a greater risk of infection by other threats.

It poses as an antispyware application that uses pop-up messages displayed on the System Tray to make users think that their systems are infected. This tricks users to purchase the complete version of the said application. It poses as an antispyware application that displays deceptive warnings and misleading scan results. It may also add other applications which it detects upon its installation. It displays fake alerts that warn users of infection. It also displays fake scanning results of the affected system. It then asks for users to purchase it once scanning is completed. If users decide to purchase the rogue product, users are directed to a certain website asking for sensitive information, such as credit card numbers.

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 component file(s):

• %Application Data%\1rgtu3e347th03
• %Application Data%\GDIPFONTCACHEV1.DAT
• %User Profile%\1rgtu3e347th03
• %User Profile%\Application Data\1rgtu3e347th03
• %User Temp%\1rgtu3e347th03
• %User Profile%\Templates\1rgtu3e347th03

(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 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.)

Autostart Technique

This Trojan employs registry shell spawning to ensure its execution when certain file types are accessed by adding the following entries:

HKEY_CLASSES_ROOT\.exe\shell\
open\command
@ = "{malware path and file name}.exe" -a "%1" %*

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\open\
command
@ = "{malware path and file name}.exe" -a "%1" %*

HKEY_CURRENT_USER\Software\Classes\
exefile\shell\open\
command
@ = "{malware path and file name}.exe" -a "%1" %*

Other System Modifications

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

HKEY_CLASSES_ROOT\.exe\DefaultIcon

HKEY_CLASSES_ROOT\.exe\shell

HKEY_CURRENT_USER\Software\Classes\
.exe

HKEY_CURRENT_USER\Software\Classes\
exefile

It modifies the following registry entries:

HKEY_CLASSES_ROOT\exefile\shell\
open\command
@ = "{malware path and file name}.exe" -a "%1" %*

(Note: The default value data of the said registry entry is "%1" %*.)

Download Routine

This Trojan connects to the following malicious URLs:

• http://{BLOCKED}beze.com/1015000112

Rogue Antivirus Routine

This Trojan poses as an antispyware application that uses pop-up messages on the System Tray to make users think that their systems are infected. This tricks users to purchase the complete version of the said application.

It poses as an antispyware application that displays deceptive warnings and misleading scan results. It may also add other applications which it detects upon its installation.

It displays fake alerts that warn users of infection. It also displays fake scanning results of the affected system. It then asks for users to purchase it once scanning is completed. If users decide to purchase the rogue product, users are directed to a certain website asking for sensitive information, such as credit card numbers.