TROJ_FAKEAV.DZY

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 downloaded by other malware/grayware/spyware from remote sites.

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

It modifies certain registry entries to disable Security Center functions. Doing this allows this malware to execute its routines without being detected. It bypasses the Windows firewall. This allows the malware to perform its intended routine without being detected by an installed firewall.

It steals certain information from the system and/or the user.

It deletes the initially executed copy of itself.

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.

File Size: 356,352 bytes

File Type: EXE

Memory Resident: Yes

Initial Samples Received Date: 30 Jul 2011

Payload: Displays message/message boxes, , Steals information, Bypasses Windows Firewall

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 downloaded by other malware/grayware/spyware from remote sites.

Installation

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

%Application Data%\{random filename}.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 drops the following non-malicious files:

%System Root%\Documents and Settings\All Users\Application Data\{random file name}
%Application Data%\{random file name}
%User Temp%\{random file name}
%User Profile%\Templates\{random file name}
%Application Data%\GDIPFONTCACHEV1.DAT - a non malicious file used by Microsoft Windows as a cache for storing font data

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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 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.. %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.)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

ir4cnxm3oi333
{C9A34C77-4D69-45EC-A07D-83242376045D}

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 numbers} = %Application Data%\{random filename}.exe

It 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
@ = ""%Application Data%\{random filename}.exe" -a "%1" %*"

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\open\
command
@ = ""%Application Data%\{random filename}.exe" -a "%1" %*"

HKEY_CURRENT_USER\Software\Classes\
exefile\shell\open\
command
@ = ""%Application Data%\{random filename}.exe" -a "%1" %*"

HKEY_CLASSES_ROOT\exefile\shell\
open\command
{default} = ""%Application Data%\{random filename}.exe" -a "%1" %*"

Other System Modifications

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

HKEY_CLASSES_ROOT\exefile\shell\
open\command
{default} = ""%Application Data%\{random filename}.exe" -a "%1" %*"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Clients\
StartMenuInternet\FIREFOX.EXE\shell\
open\command
{default} = ""%Application Data%\{random filename}.exe" -a "%Program Files%\Mozilla Firefox\firefox.exe""

(Note: The default value data of the said registry entry is "%Program Files%\Mozilla Firefox\firefox.exe".)

HKEY_LOCAL_MACHINE\SOFTWARE\Clients\
StartMenuInternet\FIREFOX.EXE\shell\
safemode\command
{default} = ""%Application Data%\{random filename}.exe" -a "%Program Files%\Mozilla Firefox\firefox.exe" -safe-mode"

(Note: The default value data of the said registry entry is ""%Program Files%\Mozilla Firefox\firefox.exe" -safe-mode".)

HKEY_LOCAL_MACHINE\SOFTWARE\Clients\
StartMenuInternet\IEXPLORE.EXE\shell\
open\command
{default} = ""%Application Data%\{random filename}.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 Security Center functions:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusDisableNotify = 1