WORM_AUTORUN.FJW
Worm:Win32/Autorun.AFY (Microsoft); W32/Autorun.worm!oa (McAfee); Downloader (Symantec); Worm.Win32.AutoRun.fzc (Kaspersky); Trojan.Win32.Generic!SB.0 (Sunbelt)
Windows 2000, Windows XP, Windows Server 2003
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:
- %System%\MSCSMC.exe
- %System%\NSMCSE.exe
- %System%\MScdent.exe
- %System%\wbm\wmiprvse.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
It creates the following folders:
- %System%\wbm
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Taskman = "%System%\MSCSMC.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,%System%\MScdent.exe"
(Note: The default value data of the said registry entry is %Windows%\system32\userinit.exe,.)
It registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\PublicProfile
Other System Modifications
This worm deletes the following files:
- %System%\MScdent.exe
- %System%\wbm\wmiprvse.exe
- %User Startup%\Service.exe
- %Common Startup%\Service.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.. %Common Startup% is the system's shared Startup folder, which is usually C:\Windows\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\All Users\Programs\Startup on Windows NT, and C:\Documents and Settings\All Users\Start Menu\Programs\Startup on Windows 2000, XP, and Server 2003.)
It adds the following registry keys:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce
HKEY_CURRENT_USER\Software\Microsoft\
Windows\Windows Error Reporting
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
DirectPer\Per
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
Run = "%System%\MScdent.exe"
HKEY_CURRENT_USER\Software\Microsoft\
DirectPer\Per
DCount = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\Windows Error Reporting
DontShowUI = "1"
HKEY_CURRENT_USER\Software\Microsoft\
DirectPer\Per
DCountmp = "13"
HKEY_CURRENT_USER\Software\Microsoft\
DirectPer\Per
Count = "1"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\PublicProfile
EnableFirewall = "0"
HKEY_CURRENT_USER\Software\Microsoft\
DirectPer\Per
Signature = "1186512"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
EnableFirewall = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
load = "%System%\NSMCSE.exe"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\UPS
ImagePath = "%System%\wbm\wmiprvse.exe"
(Note: The default value data of the said registry entry is {random values}.)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\UPS
Start = "2"
(Note: The default value data of the said registry entry is 3.)
Dropping Routine
This worm drops the following files:
- %System%\wbm\desktop.ini
- %Windows%\Tasks\Sctasks.job
- %User Startup%\Service.exe
- %Common Startup%\Service.exe
- %System%\NSMCSE.exe
- %System%\MScdent.exe
- %System%\wbm\wmiprvse.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.. %Common Startup% is the system's shared Startup folder, which is usually C:\Windows\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\All Users\Programs\Startup on Windows NT, and C:\Documents and Settings\All Users\Start Menu\Programs\Startup on Windows 2000, XP, and Server 2003.)
This report is generated via an automated analysis system.
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
Identify and delete files detected as WORM_AUTORUN.FJW 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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy
- PublicProfile
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
- RunOnce
- In HKEY_CURRENT_USER\Software\Microsoft\Windows
- Windows Error Reporting
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\DirectPer
- Per
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 NT\CurrentVersion\Winlogon
- Taskman = "%System%\MSCSMC.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
- Run = "%System%\MScdent.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\DirectPer\Per
- DCount = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\Windows Error Reporting
- DontShowUI = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\DirectPer\Per
- DCountmp = "13"
- In HKEY_CURRENT_USER\Software\Microsoft\DirectPer\Per
- Count = "1"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\PublicProfile
- EnableFirewall = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\DirectPer\Per
- Signature = "1186512"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile
- EnableFirewall = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- ShowSuperHidden = "0"
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\Windows NT\CurrentVersion\Windows
- load = "%System%\NSMCSE.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\UPS
- From: ImagePath = "%System%\wbm\wmiprvse.exe"
To: ImagePath = ""{random values}""
- From: ImagePath = "%System%\wbm\wmiprvse.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\UPS
- From: Start = "2"
To: Start = ""3""
- From: Start = "2"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: Userinit = "%System%\userinit.exe,%System%\MScdent.exe"
To: Userinit = ""%Windows%\system32\userinit.exe,""
- From: Userinit = "%System%\userinit.exe,%System%\MScdent.exe"
Step 6
Search and delete these files
- %System%\wbm\desktop.ini
- %Windows%\Tasks\Sctasks.job
- %User Startup%\Service.exe
- %Common Startup%\Service.exe
- %System%\NSMCSE.exe
- %System%\MScdent.exe
- %System%\wbm\wmiprvse.exe
Step 7
Search and delete this folder
- %System%\wbm
Step 8
Scan your computer with your Trend Micro product to delete files detected as WORM_AUTORUN.FJW. 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 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.
- %System%\MScdent.exe
- %System%\wbm\wmiprvse.exe
- %User Startup%\Service.exe
- %Common Startup%\Service.exe
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