WORM_OTORUN.GQ
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 arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.
It executes the files it drops, prompting the affected system to exhibit the malicious routines they contain.
TECHNICAL DETAILS
171,453 bytes
EXE
Yes
29 Jul 2011
Arrival Details
This worm arrives by connecting affected removable drives to a system.
It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Installation
This worm drops the following file(s)/component(s):
- %System%\bgdferw0.dll
- %System%\hyrteas0.dll
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
It drops the following copies of itself into the affected system:
- %System%\oukdfgr.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
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
hjdsdse = "%System%\oukdfgr.exe"
Other System Modifications
This worm modifies the following registry entries to hide files with Hidden attributes:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"
(Note: The default value data of the said registry entry is 1.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"
(Note: The default value data of the said registry entry is 1.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL
CheckedValue = "0"
(Note: The default value data of the said registry entry is 1.)
Propagation
This worm drops the following copy of itself in all physical and removable drives:
- lhylec9x.cmd
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]
;{garbage}
open=lhylec9x.cmd
;{garbage}
shell\open\Command=lhylec9x.cmd
Dropping Routine
This worm executes the files it drops, prompting the affected system to exhibit the malicious routines they contain.
SOLUTION
8.900
8.320.08
31 Jul 2011
8.321.00
31 Jul 2011
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
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_CURRENT_USER\Software\Microsoft\Widows\CurrentVersion\Run
- hjdsdse = "%System%\oukdfgr.exe"
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: Hidden = "2"
- Hidden = 1
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: ShowSuperHidden = "0"
- To: ShowSuperHidden = 1
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
- From: CheckedValue = "0"
- To: CheckedValue = 1
Step 5
Search and delete this file
- %System%\bgdferw0.dll
- %System%\hyrteas0.dll
Step 6
Search and delete AUTORUN.INF files created by WORM_OTORUN.GQ that contain these strings
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as WORM_OTORUN.GQ. 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.