TROJ_FAKEAV.SMX8
Microsoft : Trojan:Win32/FakeSysdef; Mcafee : FakeAlert-SysDef.b
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.
TECHNICAL DETAILS
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 copies of itself into the affected system:
- %System Root%:\Documents and Settings\All Users\Application Data\{random filename}.exe
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
It drops the following files:
- %Desktop%\{Operating System} Restore.lnk - shortcut file
- %Start Menu%\Programs\{Operating System} Restore\Uninstall {Operating System} Restore.lnk - shortcut file
- %Start Menu%\Programs\{Operating System} Restore\{Operating System} Restore.lnk - shortcut file
- %System Root%\Documents and Settings\All Users\Application Data\{numbers} - encrypted component
(Note: %Desktop% is the current user's desktop, which is usually C:\Windows\Profiles\{user name}\Desktop on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Desktop on Windows NT, and C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003.. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Profiles\{user name}\Start Menu on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu on Windows NT and C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
It drops the following file(s)/component(s):
- %System Root%\Documents and Settings\All Users\Application Data\{numbers}.exe - also detected as TROJ_FAKEAV.SMX8
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
It creates the following folders:
- %Start Menu%\Programs\{Operating System} Restore
(Note: %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Profiles\{user name}\Start Menu on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu on Windows NT and C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003.)
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 filename} = %System Root%\Documents and Settings\All Users\Application Data\{random filename}.exe
Other System Modifications
This Trojan adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Associations
LowRiskFileTypes = /{hq:/s`s:/ogn:/uyu:/dyd:/c`u:/bnl:/ble:/sdf:/lrh:/iul:/iulm:/fhg:/clq:/kqf:/`wh:/lqf:/lqdf:/lnw:/lq2:/l2t:/v`w:/rbs:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Attachments
SaveZoneInformation = 1
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = 1
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
DisableTaskMgr = 1
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
ActiveDesktop
NoChangingWallPaper = 1
HKEY_CURRENT_USER\Software
75fa38b7-8b94-4995-ad32-52e938867954 =
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Download
CheckExeSignatures = no
(Note: The default value data of the said registry entry is yes.)
Rogue Antivirus Routine
This Trojan displays the following fake alerts:
NOTES:
It hides all files on the system.
- http://{BLOCKED}ant.org/404.php?
- http://{BLOCKED}ant.org/customers/buy.php?
SOLUTION
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Restart in Safe Mode
Step 3
Search and delete this file
Step 4
Search and delete these folders
Step 5
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {random filename} = %System Root%\Documents and Settings\All Users\Application Data\{random filename}.exe
- {random filename} = %System Root%\Documents and Settings\All Users\Application Data\{random filename}.exe
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Associations
- LowRiskFileTypes = /{hq:/s`s:/ogn:/uyu:/dyd:/c`u:/bnl:/ble:/sdf:/lrh:/iul:/iulm:/fhg:/clq:/kqf:/`wh:/lqf:/lqdf:/lnw:/lq2:/l2t:/v`w:/rbs:
- LowRiskFileTypes = /{hq:/s`s:/ogn:/uyu:/dyd:/c`u:/bnl:/ble:/sdf:/lrh:/iul:/iulm:/fhg:/clq:/kqf:/`wh:/lqf:/lqdf:/lnw:/lq2:/l2t:/v`w:/rbs:
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Attachments
- SaveZoneInformation = 1
- SaveZoneInformation = 1
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
- DisableTaskMgr = 1
- DisableTaskMgr = 1
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
- DisableTaskMgr = 1
- DisableTaskMgr = 1
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\ActiveDesktop
- NoChangingWallPaper = 1
- NoChangingWallPaper = 1
- In HKEY_CURRENT_USER\Software
- 75fa38b7-8b94-4995-ad32-52e938867954 =
- 75fa38b7-8b94-4995-ad32-52e938867954 =
Step 6
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_CURRENT_USER\Software\Microsoft\Internet Explorer\Download
- From: CheckExeSignatures = no
To: CheckExeSignatures = yes
- From: CheckExeSignatures = no
Step 7
Scan your computer with your Trend Micro product to delete files detected as TROJ_FAKEAV.SMX8. 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.
NOTES:
Unhide Files
To unhide the files hidden by this malware, perform the following steps:
1. Open Command Prompt. Click Start>Programs>Accessories>Command Prompt
2. For every drive in the computer, type the following command: attrib -h "{drive letter}:\*.* /s /d
3. Close Command Prompt by typing the following command: Exit
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