WORM_FOXHIEX.C
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm 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 worm 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 worm drops the following copies of itself into the affected system:
- %User Temp%\Registry\Registry.exe
(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 creates the following folders:
- %User Temp%\Registry
- %User Profile%\My Documents\MSDCSC
- %User Profile%\Application Data\dclogs
(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.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Registry = "%User Temp%\Registry\Registry.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
MicroUpdate = "%User Profile%\MSDCSC\msdcsc.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Windows Update = "%User Profile%\Application Data\WindowsUpdate.exe"
It modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
UserInit = "%System%\userinit.exe,%User Profile%\MSDCSC\msdcsc.exe"
(Note: The default value data of the said registry entry is %Windows%\system32\userinit.exe,.)
Other System Modifications
This worm modifies the following file(s):
- %Application Data%\GDIPFONTCACHEV1.DAT
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)
It deletes the following files:
- {malware path and file name}:zone.identifier
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.268.268546
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.268.268562
- %User Profile%\v2.0.50727.42\security.config.cch.268.269093
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.768.289718
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.768.289718
- %User Profile%\v2.0.50727.42\security.config.cch.768.290593
- %User Profile%\Application Data\Windows Update.exe
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.2288.317890
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.2288.317906
- %User Profile%\v2.0.50727.42\security.config.cch.2288.318781
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.2320.318406
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.2320.318406
- %User Profile%\v2.0.50727.42\security.config.cch.2320.319156
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.2760.352921
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.2760.352921
- %User Profile%\v2.0.50727.42\security.config.cch.2760.354046
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.2924.368968
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.2924.369109
- %User Profile%\v2.0.50727.42\security.config.cch.2924.369765
(Note: %Windows% is the Windows folder, which is usually C:\Windows.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
It adds the following registry keys:
HKEY_CURRENT_USER\Software\DC3_FEXEC
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\SECURITY
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\SECURITY\
DEBUG
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
GDIPlus
FontCachePath = "%Application Data%"
(Note: The default value data of the said registry entry is %User Profile%\Local Settings\Application Data.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
EventMessageFile = "%System%\ESENT.dll"
(Note: The default value data of the said registry entry is {random values}.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
CategoryMessageFile = "%System%\ESENT.dll"
(Note: The default value data of the said registry entry is {random values}.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
CategoryCount = "1"
(Note: The default value data of the said registry entry is 10.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
TypesSupported = "7"
(Note: The default value data of the said registry entry is 7.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "1"
(Note: The default value data of the said registry entry is 2.)
Dropping Routine
This worm drops the following files:
- %User Temp%\DEFENDER.EXE
- %User Temp%\SECURITY.EXE
- %User Temp%\SysInfo.txt
- %User Profile%\Application Data\pid.txt
- %User Profile%\Application Data\pidloc.txt
- %User Profile%\MSDCSC\msdcsc.exe
- %User Profile%\Application Data\Windows Update.exe
- %User Profile%\Application Data\WindowsUpdate.exe
(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.. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
This report is generated via an automated analysis system.
SOLUTION
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
Identify and delete files detected as WORM_FOXHIEX.C using either the Startup Disk or Recovery Console
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.
- In HKEY_CURRENT_USER\Software
- DC3_FEXEC
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ESENT\Process
- SECURITY
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ESENT\Process\SECURITY
- DEBUG
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
- Registry = "%User Temp%\Registry\Registry.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- MicroUpdate = "%User Profile%\MSDCSC\msdcsc.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Windows Update = "%User Profile%\Application Data\WindowsUpdate.exe"
Step 5
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Software\Microsoft\GDIPlus
- From: FontCachePath = "%Application Data%"
To: FontCachePath = ""%User Profile%\Local Settings\Application Data""
- From: FontCachePath = "%Application Data%"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
- From: EventMessageFile = "%System%\ESENT.dll"
To: EventMessageFile = ""{random values}""
- From: EventMessageFile = "%System%\ESENT.dll"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
- From: CategoryMessageFile = "%System%\ESENT.dll"
To: CategoryMessageFile = ""{random values}""
- From: CategoryMessageFile = "%System%\ESENT.dll"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
- From: CategoryCount = "1"
To: CategoryCount = ""10""
- From: CategoryCount = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
- From: TypesSupported = "7"
To: TypesSupported = ""7""
- From: TypesSupported = "7"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: Hidden = "1"
To: Hidden = ""2""
- From: Hidden = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: UserInit = "%System%\userinit.exe,%User Profile%\MSDCSC\msdcsc.exe"
To: UserInit = ""%Windows%\system32\userinit.exe,""
- From: UserInit = "%System%\userinit.exe,%User Profile%\MSDCSC\msdcsc.exe"
Step 6
Search and delete these components
- %User Temp%\DEFENDER.EXE
- %User Temp%\SECURITY.EXE
- %User Temp%\SysInfo.txt
- %User Profile%\Application Data\pid.txt
- %User Profile%\Application Data\pidloc.txt
- %User Profile%\MSDCSC\msdcsc.exe
- %User Profile%\Application Data\Windows Update.exe
- %User Profile%\Application Data\WindowsUpdate.exe
Step 7
Search and delete these folders
- %User Temp%\Registry
- %User Profile%\My Documents\MSDCSC
- %User Profile%\Application Data\dclogs
Step 8
Scan your computer with your Trend Micro product to delete files detected as WORM_FOXHIEX.C. 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 9
Restore deleted/modified files and/or registry entries from backup
*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- %Application Data%\GDIPFONTCACHEV1.DAT
Step 10
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- {malware path and file name}:zone.identifier
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.268.268546
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.268.268562
- %User Profile%\v2.0.50727.42\security.config.cch.268.269093
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.768.289718
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.768.289718
- %User Profile%\v2.0.50727.42\security.config.cch.768.290593
- %User Profile%\Application Data\Windows Update.exe
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.2288.317890
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.2288.317906
- %User Profile%\v2.0.50727.42\security.config.cch.2288.318781
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.2320.318406
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.2320.318406
- %User Profile%\v2.0.50727.42\security.config.cch.2320.319156
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.2760.352921
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.2760.352921
- %User Profile%\v2.0.50727.42\security.config.cch.2760.354046
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.2924.368968
- %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.2924.369109
- %User Profile%\v2.0.50727.42\security.config.cch.2924.369765
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