WORM_AUTORUN.XPL
Windows 2000, XP, Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This worm drops copies of itself in all removable and physical drives found in the system. 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
Installation
This worm adds the following folders:
- %Windows%\BackUp
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)
It drops the following copies of itself into the affected system:
- %Drive%\explorer.exe
- %Windows%\BackUp\explorer.exe
- %Program Files%\explorer.exe
- %Program Files%\{17350501621331}.exe
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %Program Files% is the default Program Files folder, usually C:\Program Files.)
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
explorer = %WINDOWS%\BackUp\explorer.exe
Other System Modifications
This worm adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion
{17350501621331} = %Drive%\explorer.exe
Propagation
This worm drops copies of itself in all removable and physical drives found in the system.
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=explorer.exe
shellexecute=explorer.exe
shell\Explore\command=explorer.exe
shell\Open\command=explorer.exe
shell=Explore
SOLUTION
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Search and delete this folder
Step 3
Search and delete AUTORUN.INF files created by WORM_AUTORUN.XPL that contain these strings
open=explorer.exe
shellexecute=explorer.exe
shell\Explore\command=explorer.exe
shell\Open\command=explorer.exe
shell=Explore
Step 4
Scan your computer with your Trend Micro product to delete files detected as WORM_AUTORUN.XPL. 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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