WORM_AUTORUN.SMT
Windows 2000, Windows XP, Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This worm arrives via 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.
TECHNICAL DETAILS
72,704 bytes
Yes
02 Mar 2010
Arrival Details
This worm arrives via removable drives.
Installation
This worm drops the following copies of itself into the affected system:
- %Windows%\Wnet.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
It drops the following component file(s):
- %Windows%\ud.sys
(Note: %Windows% is the Windows folder, which is usually C:\Windows.)
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
MSN = "%Windows%\Wnet.exe"
Propagation
This worm creates the following folders in all removable drives:
- RECYCLER
- RECYCLER\S-1-6-21-2434476501-1644491937-600003330-1213
It drops the following copy(ies) of itself in all removable drives:
- RECYCLER\S-1-6-21-2434476501-1644491937-600003330-1213\flasher.exe
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=RECYCLER\S-1-6-21-2434476501-1644491937-600003330-1213\flasher.exe
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files
shell\open=Open
shell\open\command=RECYCLER\S-1-6-21-2434476501-1644491937-600003330-1213\flasher.exe
shell\open\default=1
SOLUTION
9.200
6.886.05
02 Mar 2010
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
Terminate a malware/grayware process
*Note: If the detected process is not displayed in theWindows Task Manager, continue doing the next steps.
- %Windows%\Wnet.exe
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
- MSN = %Windows%\Wnet.exe
- MSN = %Windows%\Wnet.exe
Step 4
Search and delete this folder
- {drive letter}\RECYCLER
Step 5
Search and delete AUTORUN.INF files created by WORM_AUTORUN.SMT that contain these strings
[AutoRun]
open=RECYCLER\S-1-6-21-2434476501-1644491937-600003330-1213\flasher.exe
icon=ϿstemRootϿystem32\SHELL32.dll,4
action=Open folder to view files
shell\open=Open
shell\open\command=RECYCLER\S-1-6-21-2434476501-1644491937-600003330-1213\flasher.exe
shell\open\default=1
Step 6
Scan your computer with your Trend Micro product to delete files detected as WORM_AUTORUN.SMT. 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.
Did this description help? Tell us how we did.