WORM_OTORUN.CIA
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Worm
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This worm arrives by connecting affected removable drives to a system. It may be unknowingly downloaded by a user while visiting malicious websites.
It 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
Arrival Details
This worm arrives by connecting affected removable drives to a system.
It may be unknowingly downloaded by a user while visiting malicious websites.
Installation
This worm drops the following copies of itself into the affected system:
- %Application Data%\taskhost.exe
- [drive]\viewDrive.exe
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Windows Task Host = %Application Data%\taskhost.exe
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Windows Task Host = %Application Data%\taskhost.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=viewdrive.exe
default=1
action=Open folder to view drive
shell\open\command=viewDrive.exe
shell\explore\command=viewDrive.exe
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
Identify and terminate files detected as WORM_OTORUN.CIA
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- Windows Task Host = %Application Data%\taskhost.exe
- Windows Task Host = %Application Data%\taskhost.exe
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- Windows Task Host = %Application Data%\taskhost.exe
- Windows Task Host = %Application Data%\taskhost.exe
Step 4
Search and delete AUTORUN.INF files created by WORM_OTORUN.CIA that contain these strings
Step 5
Scan your computer with your Trend Micro product to delete files detected as WORM_OTORUN.CIA. 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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