TROJ_FAKESYS.KG
Trojan:Win32/FakeSysdef (Microsoft), FakeAlert-SysDef.al (McAfee), UltraDefragFraud!gen16 (Symantec), Mal/FakeAV-RY (Sophos), Trojan.Win32.FakeSysDef.atz (v) (Sunbelt)
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
254,464 bytes
EXE
Yes
14 Aug 2012
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 Users' Profile}\Application Data\{random file name}.exe
It drops the following files:
- {All Users' Profile}\Application Data\{random file name}
- %User Profile%\Application Data\Microsoft\Internet Explorer\Quick Launch\File_Recovery.lnk
- %Desktop%\File_Recovery.lnk
- %Start Menu%\Programs\File Recovery\File Recovery.lnk
- %Start Menu%\Programs\File Recovery\Uninstall File Recovery.lnk
(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.. %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.)
It creates the following folders:
- %Start Menu%\Programs\File Recovery
(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 file name} = "{All Users' 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
WarnOnZoneCrossing = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
WarnonBadCertRecving = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
CertificateRevocation = "0"
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;"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Attachments
SaveZoneInformation = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\{random file name}\
DEBUG
Trace level = ""
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.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings\
Zones\3
1601 = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\WinTrust\
Trust Providers\Software Publishing
State = "23e00"
(Note: The default value data of the said registry entry is "23c00".)
Other Details
This Trojan connects to the following possibly malicious URL:
- http://{BLOCKED}isful.com
- http://{BLOCKED}tal.com
- http://{BLOCKED}tmemo.com
- http://{BLOCKED}nrid.com
SOLUTION
9.200
9.322.02
14 Aug 2012
9.323.00
15 Aug 2012
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_FAKESYS.KG
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- {random file name} = "{All Users' Profile}\Application Data\{random file name}.exe"
- {random file name} = "{All Users' 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
- WarnOnZoneCrossing = "0"
- WarnOnZoneCrossing = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
- WarnonBadCertRecving = "0"
- WarnonBadCertRecving = "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"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ESENT\Process\{random file name}\DEBUG
- Trace Level = ""
- Trace Level = ""
Step 5
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"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\WinTrust\Trust Providers\Software Publishing
- From: State = "23e00"
To: State = "23c00"
- From: State = "23e00"
Step 6
Reset Internet security settings
Step 7
Search and delete these files
- {All Users' Profile}\Application Data\{random file name}
- %User Profile%\Application Data\Microsoft\Internet Explorer\Quick Launch\File_Recovery.lnk
- %Desktop%\File_Recovery.lnk
Step 8
Search and delete this folder
- %Start Menu%\Programs\File Recovery
Step 9
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_FAKESYS.KG. 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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