VBS_OTORUN.SQ
Symantec : VBS.Runauto; Mcafee : VBS/Autorun.worm.k
Windows 2000, XP, Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
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.
TECHNICAL DETAILS
15,281,796 bytes
Script
Yes
11 Jan 2011
Installation
This worm drops the following copies of itself into the affected system:
- %WINDOWS%\Thumbs.vbs
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:
- Thumbs.vbs
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
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
Restart in Safe Mode
Step 3
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\CurrentVersion\Run
- avctrl = wscript.exe %windows%\Thumbs.vbs
- avctrl = wscript.exe %windows%\Thumbs.vbs
Step 4
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_CLASSES_ROOT\VBSFile
- From: @ = Configuration Script
To: @ = VBScript Script File
- From: @ = Configuration Script
Step 5
Search and delete AUTORUN.INF files created by VBS_OTORUN.SQ that contain these strings
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.
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