TROJ_FAKESYS.TA
Trojan:Win32/FakeSysdef (Microsoft), a variant of Win32/Kryptik.AUQV trojan (Eset)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
Dropped by other malware, Downloaded from the Internet
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 itself after execution.
TECHNICAL DETAILS
294,912 bytes
EXE
Yes
21 Feb 2013
Connects to URLs/IPs, Steals information, Downloads files, Drops files
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:
- %User Temp%\{random}.exe.tmp
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It drops the following copies of itself into the affected system and executes them:
- {All User's Profile}\Application Data\{random}.exe
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} = "{All User's Profile}\Application Data\{random}.exe"
Other System Modifications
This Trojan adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Attachments
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Associations
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
It adds the following registry entries:
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_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
DisableTaskMgr = "1"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\Session Manager
PendingFileRenameOperations = "\??\%User Temp%\{random}.exe.tmp"
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.)
It modifies the following registry entries to hide files with Hidden attributes:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"
(Note: The default value data of the said registry entry is 1.)
Other Details
This Trojan connects to the following possibly malicious URL:
- {BLOCKED}sondent.com
- {BLOCKED}tlingv.com
- {BLOCKED}etbeav.com
- {BLOCKED}raverse.com
- {BLOCKED}keve.com
- {BLOCKED}oveentoes.com
- {BLOCKED}agarci.com
It deletes itself after execution.
SOLUTION
9.300
9.741.00
21 Feb 2013
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Restart in Safe Mode
Step 3
Delete this registry key
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.
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Attachments
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Associations
- HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
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}= "{All User's Profile}\Application Data\{random}.exe"
- {random}= "{All User's Profile}\Application Data\{random}.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
- DisableTaskMgr = "1"
- DisableTaskMgr = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager
- PendingFileRenameOperations = "\??\%User Temp%\{random}.exe.tmp"
- PendingFileRenameOperations = "\??\%User Temp%\{random}.exe.tmp"
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\Explorer\Advanced
- From: Hidden = "0"
To: Hidden = "1"
- From: Hidden = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: ShowSuperHidden = "0"
To: ShowSuperHidden = "1"
- From: ShowSuperHidden = "0"
Step 6
Search and delete these files
- %User Temp%\{random}.exe
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_FAKESYS.TA. 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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