TROJ_FAKEAV.ZXJ
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
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 modifies certain registry entries to disable Security Center functions. Doing this allows this malware to execute its routines without being detected.
However, as of this writing, the said sites are inaccessible.
It installs a fake antivirus/antispyware software. 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.
TECHNICAL DETAILS
339,968 bytes
EXE
Yes
31 Mar 2011
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 file(s)/component(s):
- %System Root%\Documents and Settings\All Users\Application Data\{random characters}
- %User Profile%\Local Settings\Application Data\{random characters}
- %User Profile%\Local Settings\Temp\{random characters}
- %User Profile%\Templates\{random characters}
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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 drops the following copies of itself into the affected system:
- %User Profile%\Local Settings\Application Data\{random}.exe
(Note: %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.)
Other System Modifications
This Trojan adds the following registry entries as part of its installation routine:
HKEY_CLASSES_ROOT\.exe\DefaultIcon
Default = "%1"
HKEY_CLASSES_ROOT\.exe\shell\
open\command
(Default) = "%User Profile%\Local Settings\Application Data\{random}.exe" -a "%1" %*
HKEY_CLASSES_ROOT\.exe\shell\
runas\command
(Default) = "%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 entries:
HKEY_CLASSES_ROOT\exefile\shell\
open\command
(Default) = "%User Profile%\Local Settings\Application Data\{random}.exe" -a "%1" %*
(Note: The default value data of the said registry entry is "%1" %*.)
HKEY_LOCAL_MACHINE\SOFTWARE\Clients\
StartMenuInternet\FIREFOX.EXE\shell\
open\command
(Default) = "%User Profile%\Local Settings\Application Data\{random}.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) = "%User Profile%\Local Settings\Application Data\{random}.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) = "%User Profile%\Local Settings\Application Data\{random}.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_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 modifies the following registry entries to disable Security Center functions:
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
FirewallDisableNotify = 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\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
Start = 4
(Note: The default value data of the said registry entry is 2.)
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}.{BLOCKED}.197.32
However, as of this writing, the said sites are inaccessible.
Rogue Antivirus Routine
This Trojan installs a fake antivirus/antispyware software.
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.
SOLUTION
8.900
7.942.01
31 Mar 2011
Step 1
Identify and terminate files detected as TROJ_FAKEAV.ZXJ
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 2
Delete this registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_CLASSES_ROOT\.exe\shell
- open
- open
- In HKEY_CLASSES_ROOT\.exe\shell
- runas
- runas
- In HKEY_CLASSES_ROOT\exefile\shell
- open
- open
- In HKEY_CLASSES_ROOT\exefile\shell
- runas
- runas
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile
- EnableFirewall="1"
- EnableFirewall="1"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile
- DoNotAllowExceptions="0"
- DoNotAllowExceptions="0"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile
- DisableNotifications="1"
- DisableNotifications="1"
Step 3
Restore this modified registry value
Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.
- In HKEY_CLASSES_ROOT\exefile\shell\open\command
- From: (Default)=%User Profile%\Local Settings\Application Data\{random}.exe -a %1 %*
To: (Default)=%1 %*
- From: (Default)=%User Profile%\Local Settings\Application Data\{random}.exe -a %1 %*
- In HKEY_LOCAL_MACHINE\SOFTWARE\Clients\StartMenuInternet\FIREFOX.EXE\shell\open\command
- From: (Default)=%User Profile%\Local Settings\Application Data\{random}.exe -a %Program Files%\Mozilla Firefox\firefox.exe
To: (Default)=%Program Files%\Mozilla Firefox\firefox.exe
- From: (Default)=%User Profile%\Local Settings\Application Data\{random}.exe -a %Program Files%\Mozilla Firefox\firefox.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\Clients\StartMenuInternet\FIREFOX.EXE\shell\safemode\command
- From: (Default)=%User Profile%\Local Settings\Application Data\{random}.exe -a %Program Files%\Mozilla Firefox\firefox.exe -safe-mode
To: (Default)=%Program Files%\Mozilla Firefox\firefox.exe -safe-mode
- From: (Default)=%User Profile%\Local Settings\Application Data\{random}.exe -a %Program Files%\Mozilla Firefox\firefox.exe -safe-mode
- In HKEY_LOCAL_MACHINE\SOFTWARE\Clients\StartMenuInternet\IEXPLORE.EXE\shell\open\command
- From: (Default)=%User Profile%\Local Settings\Application Data\{random}.exe -a %Program Files%\Internet Explorer\iexplore.exe
To: (Default)=%Program Files%\Internet Explorer\iexplore.exe
- From: (Default)=%User Profile%\Local Settings\Application Data\{random}.exe -a %Program Files%\Internet Explorer\iexplore.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- From: AntiVirusDisableNotify=1
To: AntiVirusDisableNotify=0
- From: AntiVirusDisableNotify=1
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- From: FirewallDisableNotify=1
To: FirewallDisableNotify=0
- From: FirewallDisableNotify=1
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- From: UpdatesDisableNotify=1
To: UpdatesDisableNotify=0
- From: UpdatesDisableNotify=1
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- From: AntiVirusOverride=1
To: AntiVirusOverride=0
- From: AntiVirusOverride=1
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
- From: FirewallOverride=1
To: FirewallOverride=0
- From: FirewallOverride=1
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess
- From: Start=4
To: Start=2
- From: Start=4
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- From: EnableFirewall=0
To: EnableFirewall=1
- From: EnableFirewall=0
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- From: DisableNotifications=1
To: DisableNotifications=0
- From: DisableNotifications=1
Step 4
Search and delete this file
%User Profile%\Local Settings\Application Data\{random characters}
%User Profile%\Local Settings\Temp\{random characters}
%User Profile%\Templates\{random characters}
Step 5
Scan your computer with your Trend Micro product to delete files detected as TROJ_FAKEAV.ZXJ. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.
Step 6
Restore this deleted registry key/value from backup
*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\wuauservDid this description help? Tell us how we did.