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.
It disables Task Manager, Registry Editor, and Folder Options.
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.
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
system = "%Windows%\kernel32.ini"
It modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = "explorer.exe %Windows%\smss.exe"
(Note: The default value data of the said registry entry is Explorer.exe.)
Other System Modifications
This worm adds the following registry keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer
Run = "1"
It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer
NoFolderOptions = "1"
Dropping Routine
This worm drops the following files:
- %Windows%\smss.exe
- %System%\msarti.com
- %Windows%\kernel32.ini
- %System Root%\Wilbert.exe
- %System Root%\auto.exe
- %System Root%\autorun.inf
- %Application Data%\Micros~1\CDBurn~1\auto.exe
- %Application Data%\Micros~1\CDBurn~1\autorun.inf
This report is generated via an automated analysis system.
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_SILLYFDC.CN using either the Startup Disk or Recovery Console
[ Learn More ]
[ back ]
To identify and delete the malware/grayware file:
• On Windows XP and Server 2003 systems:
- Scan your computer with your Trend Micro product and then take note of the names of the malware/grayware files detected.
- Click Start>Run. In the Open input box, type secpol.msc and press Enter.
- In the left panel, double-click Local Policies>Security Options.
- In the right panel, double-click Recovery Console: Allow floppy copy and access to all drives and folders.
- Select Enabled and click OK.
- Insert the Windows Installation CD into the CD drive, then restart your computer.
- When prompted, press any key to boot from the CD.
- On the main menu, type r to go to the Recovery Console.
- Type the number that corresponds to the drive and directory that contains Windows (usually C:\WINDOWS) and press Enter.
- Type the Administrator password and press Enter.
- In the input box, type the following then press Enter:
SET AllowAllPaths = TRUE
del "{malware/grayware path and file name}" - Type exit and press Enter to restart the system normally.
• On Windows Vista and 7 systems:
- Scan your computer with your Trend Micro product and then take note of the names of the malware/grayware files detected.
- Insert your Windows Installation DVD in the DVD drive, then Press the restart button.
- When prompted, press any key to boot from the CD.
- Depending on your Windows Installation DVD, you might be required to select the installation language. Then on the Install Windows window, choose your language, locale, and keyboard layout or input method. Click Next, then click Repair your computer.
- Select Use recovery tools that can help fix problems starting Windows. Select your installation of Windows. Click Next.
- If the Startup Repair window appears, click Cancel, Yes, then Finish.
- In the System Recovery Options window, click Command Prompt.
- In the Command Prompt window, type the following then press Enter:
BootRec.exe /fixmbr
del "{malware/grayware path and file name}" - Type exit and press Enter to close the Command Prompt window.
- Click Restart to restart the system normally.
Step 3
Enable Registry Editor, Task Manager, and Folder options
[ Learn More ]
[ back ]
By doing this step, you also enable other applications/programs disabled by this malware/grayware/spyware.
To enable Registry Editor, Task Manager, and Folder options:
- Open Notepad. To do this:
- For Windows 2000, XP, and Server 2003 users:
Click Start>Run, type Notepad in the text box provided, then press Enter. - For Windows Vista and 7 users:
Click start. Type Notepad , then press Enter.
- Copy and paste the following script:
- Save this file as C:\RESTORE.VBS.
- Click Start>Run again, type C:\RESTORE.VBS in the text box provided, then press Enter.
- Click Yes at the prompt of the message box to execute the .VBS file.
Step 4
Delete this registry key
[ Learn More ]
[ back ]
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\Policies
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
To delete the registry key this malware/grayware created:
- Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
- In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>Software>Microsoft>Windows>CurrentVersion>Policies - Still in the left panel, locate and delete the key:
Explorer - In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>Software>Microsoft>Windows>CurrentVersion>Policies>Explorer - Still in the left panel, locate and delete the key:
Run - Close Registry Editor.
Step 5
Delete this registry value
[ Learn More ]
[ back ]
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
- system = "%Windows%\kernel32.ini"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer
To delete the registry value this malware/grayware created:
- Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
- In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
system = "%Windows%\kernel32.ini" - In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows>CurrentVersion>policies>Explorer - In the right panel, locate and delete the entry:
Run = "1" - Close Registry Editor.
Step 6
Restore these modified registry values
[ Learn More ]
[ back ]
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: Shell = "explorer.exe %Windows%\smss.exe"
To: Shell = ""Explorer.exe""
To restore registry values this malware/grayware modified:
- Open Registry Editor. To do this:
- On Windows 2000, XP, and Server 2003:
Click Start>Run, type REGEDIT in the text box provided, and then press Enter. - On Windows Vista and 7:
Click the Start button, type REGEDIT in the Search input field then press Enter.
- In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows NT>CurrentVersion>Winlogon - In the right panel, locate the registry value:
Shell = "explorer.exe %Windows%\smss.exe" - Right-click on the value name and choose Modify. Change the value data of this entry to:
Shell = "Explorer.exe" - Close Registry Editor.
Step 7
Search and delete these components
[ Learn More ]
[ back ]
There may be some components that are hidden. Please make sure you check the
Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
- %Windows%\smss.exe
- %System%\msarti.com
- %Windows%\kernel32.ini
- %System Root%\Wilbert.exe
- %System Root%\auto.exe
- %System Root%\autorun.inf
- %Application Data%\Micros~1\CDBurn~1\auto.exe
- %Application Data%\Micros~1\CDBurn~1\autorun.inf
To manually delete a malware/grayware component from an affected system:
• For Windows 2000, Windows XP, and Windows Server 2003:
- Right-click Start then click Search....
- In the Named input box, type:
- %Windows%\smss.exe
- %System%\msarti.com
- %Windows%\kernel32.ini
- %System Root%\Wilbert.exe
- %System Root%\auto.exe
- %System Root%\autorun.inf
- %Application Data%\Micros~1\CDBurn~1\auto.exe
- %Application Data%\Micros~1\CDBurn~1\autorun.inf
- In the Look In drop-down list, select My Computer then press Enter.
- Once located, select the file then press SHIFT+DELETE to delete it.
- Repeat the said steps for all files listed.
• For Windows Vista and Windows 7 users:
- Click Start>Computer.
- In the Search input box, type:
- %Windows%\smss.exe
- %System%\msarti.com
- %Windows%\kernel32.ini
- %System Root%\Wilbert.exe
- %System Root%\auto.exe
- %System Root%\autorun.inf
- %Application Data%\Micros~1\CDBurn~1\auto.exe
- %Application Data%\Micros~1\CDBurn~1\autorun.inf
- Once located, select the file then press SHIFT+DELETE to delete it.
- Repeat the said steps for all files listed.
*Note: Read the following Microsoft page if these steps do not work on Windows 7.
Step 8
Scan your computer with your Trend Micro product to delete files detected as WORM_SILLYFDC.CN. 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.
