WORM_SILLY.SMD
Windows 98, ME, NT, 2000, XP, Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
It may be unknowingly downloaded by a user while visiting malicious websites.
It arrives via removable drives.
It adds registry entries to enable its automatic execution at every system startup.
It uses the default Windows folder icon to trick users into opening the file. Double-clicking on the file executes this malware.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
It drops copies of itself in all removable drives.
It drops copies of itself in removable drives. These dropped copies use the names of the folders located on the said drives for their file names.
TECHNICAL DETAILS
01 Jan 0001
Arrival Details
It may be unknowingly downloaded by a user while visiting malicious websites.
Autostart Technique
It adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
WindowMessenger=%System Root%\RECYCLER\X-1-5-21-1960408961-725345543-839522115-1003\WinSysApp.exe
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
Windows Alerter=%Program Files%\Windows Alerter\WinAlert.exe
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
Windows Common Files Manager=%Program Files%\Windows Common Files\Commgr.exe
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
WindowMessenger=%System Root%\RECYCLER\X-1-5-21-1960408961-725345543-839522115-1003\WinSysApp.exe
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Windows Alerter=%Program Files%\Windows Alerter\WinAlert.exe
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
Windows Common Files Manager=%Program Files%\Windows Common Files\Commgr.exe
Dropping Routine
It sets the attributes of its dropped file(s) to the following:
- Hidden
- Read-Only
- System
Installation
It drops the following copies of itself into the affected system:
- %Program Files%\Windows Alerter\WinAlert.exe
- %Program Files%\Windows Common Files\Commgr.exe
- %System Root%\RECYCLER\X-1-5-21-1960408961-725345543-839522115-1003\WinSysApp.exe
It drops the following files:
- %System Root%\RECYCLER\X-1-5-21-1960408961-725345543-839522115-1003\bnf0342
- %System Root%\RECYCLER\X-1-5-21-1960408961-725345543-839522115-1003\info
- %System Root%\RECYCLER\X-1-5-21-1960408961-725345543-839522115-1003\wndsvc.dll
It creates the following folders:
- %Program Files%\Windows Alerter
- %Program Files%\Windows Common Files
- %System Root%\RECYCLER\X-1-5-21-1960408961-725345543-839522115-1003
It uses the default Windows folder icon to trick users into opening the file. Double-clicking on the file executes this malware.
Other System Modifications
It modifies the following registry entries to hide files with Hidden attributes:
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CURRENTVERSION\Explorer\Advanced
Hidden=2
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CURRENTVERSION\Explorer\Advanced
SuperHidden=0
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CURRENTVERSION\Explorer\Advanced
ShowSuperHidden=0
HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CURRENTVERSION\Explorer\Advanced
HideFileExt=1
Propagation
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
It drops copies of itself in all removable drives.
It drops copies of itself in removable drives. These dropped copies use the names of the folders located on the said drives for their file names.
SOLUTION
8.900
Step 1
For Windows ME and XP 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 WORM_SILLY.SMD
Step 3
Restart in Safe Mode
Step 4
Delete this registry value This step allows you to delete the registry value created by the malware/grayware/spyware.
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
- WindowMessenger=%System Root%\RECYCLER\X-1-5-21-1960408961-725345543-839522115-1003\WinSysApp.exe
- WindowMessenger=%System Root%\RECYCLER\X-1-5-21-1960408961-725345543-839522115-1003\WinSysApp.exe
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Windows Alerter=%Program Files%\Windows Alerter\WinAlert.exe
- Windows Alerter=%Program Files%\Windows Alerter\WinAlert.exe
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Windows Common Files Manager=%Program Files%\Windows Common Files\Commgr.exe
- Windows Common Files Manager=%Program Files%\Windows Common Files\Commgr.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- WindowMessenger=%System Root%\RECYCLER\X-1-5-21-1960408961-725345543-839522115-1003\WinSysApp.exe
- WindowMessenger=%System Root%\RECYCLER\X-1-5-21-1960408961-725345543-839522115-1003\WinSysApp.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- Windows Alerter=%Program Files%\Windows Alerter\WinAlert.exe
- Windows Alerter=%Program Files%\Windows Alerter\WinAlert.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- Windows Common Files Manager=%Program Files%\Windows Common Files\Commgr.exe
- Windows Common Files Manager=%Program Files%\Windows Common Files\Commgr.exe
To delete the registry value this malware/grayware/spyware created:
- Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
- In the left panel, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
WindowMessenger=%System Root%\RECYCLER>X-1-5-21-1960408961-725345543-839522115-1003>WinSysApp.exe - In the left panel, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
Windows Alerter=%Program Files%\Windows Alerter>WinAlert.exe - In the left panel, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
Windows Common Files Manager=%Program Files%\Windows Common Files>Commgr.exe - 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:
WindowMessenger=%System Root%\RECYCLER>X-1-5-21-1960408961-725345543-839522115-1003>WinSysApp.exe - 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:
Windows Alerter=%Program Files%\Windows Alerter>WinAlert.exe - 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:
Windows Common Files Manager=%Program Files%\Windows Common Files>Commgr.exe - Close Registry Editor.
Step 5
Restore this modified registry value This step allows you to undo a change done by the malware/grayware/spyware to a 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\Explorer\Advanced
- From: Hidden=2
To: 1
- From: Hidden=2
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CURRENTVERSION\Explorer\Advanced
- From: ShowSuperHidden=0
To: 1
- From: ShowSuperHidden=0
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CURRENTVERSION\Explorer\Advanced
- From: HideFileExt=1
To: 0
- From: HideFileExt=1
To restore the registry value this malware/grayware/spyware modified:
- Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
- In the left panel, double-click the following:
HKEY_CURRENT_USER>SOFTWARE>Microsoft>Windows>CURRENTVERSION>Explorer>Advanced - In the right panel, locate the registry value:
Hidden=2 - Right-click on the value name and choose Modify. Change the value data of this entry to:
1 - In the left panel, double-click the following:
HKEY_CURRENT_USER>SOFTWARE>Microsoft>Windows>CURRENTVERSION>Explorer>Advanced - In the right panel, locate the registry value:
HKEY_CURRENT_USER>SOFTWARE>Microsoft>Windows>CURRENTVERSION>Explorer>Advanced - Right-click on the value name and choose Modify. Change the value data of this entry to:
ShowSuperHidden=0
To: 1 - In the left panel, double-click the following:
HKEY_CURRENT_USER>SOFTWARE>Microsoft>Windows>CURRENTVERSION>Explorer>Advanced - In the right panel, locate the registry value:
HKEY_CURRENT_USER>SOFTWARE>Microsoft>Windows>CURRENTVERSION>Explorer>Advanced - Right-click on the value name and choose Modify. Change the value data of this entry to:
HideFileExt=1
To: 0 - Close Registry Editor.
Step 6
Search and delete this folder This step allows you to search and delete the folder created by this malware/grayware/spyware. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
To delete the malware/grayware/spyware folder:
- Right-click Start then click Search... or Find..., depending on the version of Windows you are running.
- In the Named input box, type:
- Ͽogram FilesϿindows Alerter
Ͽogram FilesϿindows Common Files
Ͽstem RootϿECYCLERX-1-5-21-1960408961-725345543-839522115-1003
- In the Look In drop-down list, select My Computer, then press Enter.
- Once located, select the folder then press SHIFT+DELETE to permanently delete the folder.
Step 7
Search and delete AUTORUN.INF files created by WORM_SILLY.SMD that contain these strings This solution provides a basic guide in removing unwanted AUTORUN.INF files/content that are added by malware.
To identify and delete AUTORUN.INF files created:
- Right-click the Start button then choose Search... or Find..., depending on the version of Windows you are running.
- In the Named input box, type:
AUTORUN.INF - In the Look in: drop-down list, select a drive, then press Enter.
- Select the file, then open using Notepad.
- Check if the following lines are present in the file:
- If the lines are present, delete the file.
- Repeat steps 3 to 6 for the remaining AUTORUN.INF files in other remaining removable drives.
- Close Search Results.
Step 8
Scan your computer with your Trend Micro product to delete files detected as WORM_SILLY.SMD 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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