TROJ_FAKEAV.DAC

This Trojan modifies registry entries to disable the Windows Firewall settings. This action allows this malware to perform its routines without being deteted by the Windows Firewall.

It executes the files it drops, prompting the affected system to exhibit the malicious routines they contain.

It deletes itself after execution.

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.

Installation

This Trojan drops the following copies of itself into the affected system:

• %User Profile%\Local Settings\Application Data\{random three letter}.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

It drops the following files:

• %system root%\Documents and Settings\All Users\Application Data\3ucghnxb07i7cm6irx618633uore80rii22kfxm8k1w3b7
• %User Profile%\Local Settings\Application Data\3ucghnxb07i7cm6irx618633uore80rii22kfxm8k1w3b7
• %User Temp%\3ucghnxb07i7cm6irx618633uore80rii22kfxm8k1w3b7
• %User Profile%\Templates\3ucghnxb07i7cm6irx618633uore80rii22kfxm8k1w3b7

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

Other System Modifications

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

HKEY_CLASSES_ROOT\.exe\shell\
open\command
@ = "%User Profile%\Local Settings\Application Data\{random three letter}.exee" -a "%1" %*

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\open\
command
@ = "%User Profile%\Local Settings\Application Data\{random three letter}.exe" -a "%1" %*

HKEY_CURRENT_USER\Software\Classes\
exefile\shell\open\
command
@ = "%User Profile%\Local Settings\Application Data\{random three letter}.exee" -a "%1" %*

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusDisableNotify = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusOverride = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallDisableNotify = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallOverride = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
UpdatesDisableNotify = 1

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
EnableFirewall = 0

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
DoNotAllowExceptions = 0

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
DisableNotifications = 1

It modifies the following registry key(s)/entry(ies) as part of its installation routine:

HKEY_CLASSES_ROOT\exefile\shell\
open\command
@ = "%User Profile%\Local Settings\Application Data\{random three letter}.exe" -a "%1" %*

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

HKEY_LOCAL_MACHINE\SOFTWARE\Clients\
StartMenuInternet\IEXPLORE.EXE\shell\
open\command
@ = "%User Profile%\Local Settings\Application Data\{random three letter}.exe" -a "%Program Files%\Internet Explorer\iexplore.exe"

(Note: The default value data of the said registry entry is "%Program Files%\Internet Explorer\iexplore.exe".)

It modifies the following registry entries to disable the Windows Firewall settings:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = 0

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = 1

(Note: The default value data of the said registry entry is 0.)

Dropping Routine

This Trojan executes the files it drops, prompting the affected system to exhibit the malicious routines they contain.

Other Details

This Trojan deletes itself after execution.

Rogue Antivirus Routine

This Trojan 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.