This worm adds registry entries to enable its automatic execution at every system startup.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
Installation
This worm drops the following copies of itself into the affected system:
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
avctrl = wscript.exe %windows%\Thumbs.vbs
Other System Modifications
This worm modifies the following registry entries:
HKEY_CLASSES_ROOT\VBSFile
@ = Configuration Script
(Note: The default value data of the said registry entry is VBScript Script File.)
Propagation
This worm drops the following copy of itself in all physical and removable drives:
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
The said .INF file contains the following strings:
[AUTORUN]
open=wscript.exe Thumbs.vbs
icon=0
shell\install = &Install
shell\install\command = wscript.exe Thumbs.vbs
shell\uninstall = &UnInstall
shell\uninstall\command = wscript.exe Thumbs.vbs
shell\readme = &Read Me
shell\readme\command = wscript.exe Thumbs.vbs
shell\help = &Help
shell\help\command = wscript.exe Thumbs.vbs
shell\Open = &Open
shell\Open\command = wscript.exe Thumbs.vbs
shell\Open\Default=1
shell\Run = &Run
shell\Run\command = wscript.exe Thumbs.vbs
shell\Run\Default=1
shell\explore=Explorer
shell\explore\Command=Explorer.exe
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
Restart in Safe Mode
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To restart in Safe Mode:
• For Windows 98 and ME users
- Restart your computer.
- Press the CTRL key until the startup menu appears.
- Choose the Safe Mode option then press Enter.
• For Windows NT (VGA mode) users
- Click Start>Settings>Control Panel.
- Double-click the System icon.
- Click the Startup/Shutdown tab.
- Set the Show List field to 10 seconds and click OK to save this change.
- Shut down and restart your computer.
- Select VGA mode from the startup menu.
• For Windows 2000 users
- Restart your computer.
- Press the F8 key, when you see the Starting Windows bar at the bottom of the screen.
- Choose the Safe Mode option from the Windows Advanced Options Menu then press Enter.
• For Windows XP users
- Restart your computer.
- Press F8 after the Power-On Self Test (POST) is done. If the Windows Advanced Options Menu does not appear, try restarting and then pressing F8 several times after the POST screen.
- Choose the Safe Mode option from the Windows Advanced Options Menu then press Enter.
• For Windows Server 2003 users
- Restart your computer.
- Press F8 after Windows starts up. If the Windows Advanced Options Menu does not appear, try restarting again and then pressing F8 several times after restarting.
- On the Windows Advanced Option menu, use the arrow keys to select Safe Mode, and then press Enter.
Step 3
Delete this registry value
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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
- avctrl = wscript.exe %windows%\Thumbs.vbs
To delete the registry value this malware created:
- Open Registry Editor. To do this, click Start>Run, type regedit in the text box provided, then press Enter.
- In the left panel of the Registry Editor window, double-click the following:
HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
avctrl = wscript.exe %windows%\Thumbs.vbs - Close Registry Editor.
Step 4
Restore this modified registry value
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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_CLASSES_ROOT\VBSFile
- From: @ = Configuration Script
To: @ = VBScript Script File
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_CLASSES_ROOT>VBSFile - In the right panel, locate the registry value:
@ = Configuration Script - Right-click on the value name and choose Modify. Change the value data of this entry to:
@ = VBScript Script File - Close Registry Editor.
Step 5
Search and delete AUTORUN.INF files created by VBS_OTORUN.SQ that contain these strings
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[AUTORUN]
open=wscript.exe Thumbs.vbs
icon=0
shell\install = &Install
shell\install\command = wscript.exe Thumbs.vbs
shell\uninstall = &UnInstall
shell\uninstall\command = wscript.exe Thumbs.vbs
shell\readme = &Read Me
shell\readme\command = wscript.exe Thumbs.vbs
shell\help = &Help
shell\help\command = wscript.exe Thumbs.vbs
shell\Open = &Open
shell\Open\command = wscript.exe Thumbs.vbs
shell\Open\Default=1
shell\Run = &Run
shell\Run\command = wscript.exe Thumbs.vbs
shell\Run\Default=1
shell\explore=Explorer
shell\explore\Command=Explorer.exe
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:
[AUTORUN]
open=wscript.exe Thumbs.vbs
icon=0
shell\install = &Install
shell\install\command = wscript.exe Thumbs.vbs
shell\uninstall = &UnInstall
shell\uninstall\command = wscript.exe Thumbs.vbs
shell\readme = &Read Me
shell\readme\command = wscript.exe Thumbs.vbs
shell\help = &Help
shell\help\command = wscript.exe Thumbs.vbs
shell\Open = &Open
shell\Open\command = wscript.exe Thumbs.vbs
shell\Open\Default=1
shell\Run = &Run
shell\Run\command = wscript.exe Thumbs.vbs
shell\Run\Default=1
shell\explore=Explorer
shell\explore\Command=Explorer.exe
- 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 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as VBS_OTORUN.SQ 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.
