TROJ_FAKEAV.FHR

This Trojan may be dropped by other malware. It may be unknowingly downloaded by a user while visiting malicious websites.

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

It 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.

Arrival Details

This Trojan may be dropped by other malware.

It may be unknowingly downloaded by a user while visiting malicious websites.

Installation

This Trojan drops the following file(s)/component(s):

• %Application Data%\n3a4ax1ph0166w8150b7w8h53fg04xrpxnlc86
• %Temp%\n3a4ax1ph0166w8150b7w8h53fg04xrpxnlc86

(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.. %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp or C:\WINNT\Temp.)

It drops the following copies of itself into the affected system:

• %Application Data%\{3 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.)

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\{2 random characters}\shell\
open\command
(Default) = "%Application Data%\{3 random characters}.exe"

HKEY_CLASSES_ROOT\.exe\shell\
open\command
(Default) = "%Application Data%\{3 random characters}.exe"

HKEY_CLASSES_ROOT\{2 random characters}
(Default) = "Application"

HKEY_CLASSES_ROOT\{2 random characters}
Content Type = "application/x-msdownload"

HKEY_CLASSES_ROOT\{2 random characters}\DefaultIcon
(Default) = "%1"

HKEY_CLASSES_ROOT\{2 random characters}\shell\
open\command
IsolatedCommand = ""%1" %*"

HKEY_CLASSES_ROOT\{2 random characters}\shell\
runas\command
(Default) = ""%1" %*"

HKEY_CLASSES_ROOT\{2 random characters}\shell\
runas\command
IsolatedCommand = ""%1" %*"

HKEY_CLASSES_ROOT\.exe\DefaultIcon
(Default) = "%1"

HKEY_CLASSES_ROOT\.exe\shell\
open\command
IsolatedCommand = ""%1" %*"

HKEY_CLASSES_ROOT\.exe\shell\
runas\command
(Default) = ""%1" %*"

HKEY_CLASSES_ROOT\.exe\shell\
runas\command
IsolatedCommand = ""%1" %*"

HKEY_CURRENT_USER\Software\Classes\
.exe
(Default) = "{2 random characters}"

HKEY_CURRENT_USER\Software\Classes\
.exe
Content Type = "application/x-msdownload"

HKEY_CURRENT_USER\Software\Classes\
.exe\DefaultIcon
(Default) = "%1"

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\open\
command
(Default) = "%Application Data%\(3 random characters}.exe -a "%1" %*"

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\open\
command
IsolatedCommand = ""%1" %*"

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\runas\
command
(Default) = ""%1" %*"

HKEY_CURRENT_USER\Software\Classes\
.exe\shell\runas\
command
IsolatedCommand = ""%1" %*"

HKEY_CURRENT_USER\Software\Classes\
{2 random characters}
(Default) = "Application"

HKEY_CURRENT_USER\Software\Classes\
{2 random characters}
Content Type = "application/x-msdownload"

HKEY_CURRENT_USER\Software\Classes\
{2 random characters}\DefaultIcon
(Default) = "%1"

HKEY_CURRENT_USER\Software\Classes\
{2 random characters}\shell\open\
command
(Default) = "%Application Data%\{3 randomcharacters}.exe -a "%1" %*"

HKEY_CURRENT_USER\Software\Classes\
{2 random characters}\shell\open\
command
IsolatedCommand = ""%1" %*"

HKEY_CURRENT_USER\Software\Classes\
{2 random characters}\shell\runas\
command
(Default) = ""%1" %*"

HKEY_CURRENT_USER\Software\Classes\
{2 random characters}\shell\runas\
command
IsolatedCommand = ""%1" %*"

Other System Modifications

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows
Local = "a362f438"

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

HKEY_CLASSES_ROOT\{2 random characters}

HKEY_CLASSES_ROOT\.exe\shell

HKEY_CURRENT_USER\Software\Classes\
.exe

HKEY_CURRENT_USER\Software\Classes\
.exe\DefaultIcon

HKEY_CURRENT_USER\Software\Classes\
{2 random characters}

HKEY_CLASSES_ROOT\.exe\DefaultIcon

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
MessengerService
Server = "messenger.hotmail.com;64.4.61.35:1863"

(Note: The default value data of the said registry entry is messenger.hotmail.com;64.4.9.254:1863.)

HKEY_LOCAL_MACHINE\SOFTWARE\Clients\
StartMenuInternet\FIREFOX.EXE\shell\
open\command
(Default) = ""%Application Data%\{3 random characters}.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%\{3 random characters}.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%\{3 random characters}.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.)

HKEY_CLASSES_ROOT\.exe
(Default) = "2 random characters"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusDisableNotify = "1"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
UpdatesDisableNotify = "1"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusOverride = "1"

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess
Start = "4"

(Note: The default value data of the said registry entry is 2.)

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallDisableNotify = "1"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallOverride = "1"

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

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.)

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\wuauserv

Other Details

This Trojan connects to the following possibly malicious URL:

• http://{BLOCKED}ifaqago.com/1004000113