TROJ_FAKEAV.GNT
Trojan:Win32/FakeSysdef (Microsoft)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted:
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 deletes the initially executed copy of itself.
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 and executes them:
- {All User's Profile}\Application Data\{random file name}.exe
It drops the following component file(s):
- {All User's Profile}\Application Data\{random file name}
- %Start Menu%\Programs\File Restore\File Restore.lnk
- %Start Menu%\Programs\File Restore\Uninstall File Restore.lnk
- %Desktop%\File_Restore.lnk
- %User Profile%\Application Data\Microsoft\Internet Explorer\Quick Launch\File_Restore.lnk
- {All User's Profile}\Application Data\-{random file name}
- {All User's Profile}\Application Data\-{random file name}r
(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.. %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.. %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 creates the following folders:
- %Start Menu%\Programs\File 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_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{random file name} = "{All User's Profile}\Application Data\{random file name}.exe"
Other System Modifications
This Trojan adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Use FormSuggest = "Yes"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
WarnonBadCertRecving = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
WarnOnZoneCrossing = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
CertificateRevocation = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Attachments
SaveZoneInformation = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Associations
LowRiskFileTypes = ".zip;.rar;.nfo;.txt;.exe;.bat;.com;.cmd;.reg;.msi;.htm;.html;.gif;.bmp;.jpg;.avi;.mpg;.mpeg;.mov;.mp3;.m3u;.wav;.scr;"
Other Details
This Trojan connects to the following possibly malicious URL:
- {BLOCKED}.{BLOCKED}.86.61:80/p.php?0Q9oBPXEN0uECUgzEJ95RQsajjnvq1aG3F/2q5oNvBGAyHya0iCsG5//bBw9iKz11e/law==
- {BLOCKED}.{BLOCKED}.86.61:80/support/f
- {BLOCKED}.{BLOCKED}.7.44:80/support/f
- {BLOCKED}.{BLOCKED}.7.44:80/support/fr
- {BLOCKED}.{BLOCKED}.236.156:80/support/f
It deletes the initially executed copy of itself
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
Scan your computer with your Trend Micro product and note files detected as TROJ_FAKEAV.GNT
Step 3
Restart in Safe Mode
Step 4
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- {random file name} = "{All User's Profile}\Application Data\{random file name}.exe"
- {random file name} = "{All User's Profile}\Application Data\{random file name}.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
- Use FormSuggest = "Yes"
- Use FormSuggest = "Yes"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- WarnonBadCertRecving = "0"
- WarnonBadCertRecving = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- WarnOnZoneCrossing = "0"
- WarnOnZoneCrossing = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- CertificateRevocation = "0"
- CertificateRevocation = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Associations
- LowRiskFileTypes = ".zip;.rar;.nfo;.txt;.exe;.bat;.com;.cmd;.reg;.msi;.htm;.html;.gif;.bmp;.jpg;.avi;.mpg;.mpeg;.mov;.mp3;.m3u;.wav;.scr;"
- LowRiskFileTypes = ".zip;.rar;.nfo;.txt;.exe;.bat;.com;.cmd;.reg;.msi;.htm;.html;.gif;.bmp;.jpg;.avi;.mpg;.mpeg;.mov;.mp3;.m3u;.wav;.scr;"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Attachments
- SaveZoneInformation = "1"
- SaveZoneInformation = "1"
Step 5
Search and delete this folder
- %Start Menu%\Programs\File Restore
Step 6
Search and delete these files
- %Desktop%\File_Restore.lnk
- %User Profile%\Application Data\Microsoft\Internet Explorer\Quick Launch\File_Restore.lnk
- {All User's Profile}\Application Data\{random file name}
- {All User's Profile}\Application Data\-{random file name}
- {All User's Profile}\Application Data\-{random file name}r
Step 7
- Open a command prompt.
- For Windows 2000, Windows XP, and Windows Server 2003 users, click Start>Run. In the Open input box, type CMD then press Enter.
- In the CMD console, type the following:
ATTRIB [+R | -R] [+A | -A ] [+S | -S] [+H | -H] [+I | -I] [drive:][path][file name] [/S [/D] [/L]]
Where:
+ Sets an attribute.
- Clears an attribute
R Read-only file attribute
A Archive file attribute
S System file attribute
H Hidden file attribute
I Not content indexed file attribute
[drive:][path][filename]
Specifies a file or files for attrib to process
/S Processes matching files in the current folder and all subfolders.
/D Processes folders
/L Work on the attributes of the Symbolic Link versus the target of the Symbolic Link
Example:
To unhide all files and folders (including subfolders) in drive D:
ATTRIB –H D:\* /S /D
- Repeat Step 2 for folders and files in other drives or directories.
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_FAKEAV.GNT. 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.
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