WORM_ONLINEG.MBN
Windows 2000, XP, Server 2003
![](/vinfo/imgFiles/legend.jpg)
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 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 drops the following copies of itself into the affected system:
- %User Profile%\Local Settings\Temp\xvassdf.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
It drops the following files:
- %User Profile%\Local Settings\Temp\4tddfwq0.dll - detected by Trend Micro as WORM_ONLINEG.MBN
- %System%\dllcache\cdaudio.sys - non-malicious file
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows 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
54dfsger = %User Profile%\Local Settings\Temp\xvassdf.exe
Other System Modifications
This worm modifies the following registry entries:
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.)
It also creates the following registry entry(ies) as part of its installation routine:
HKEY_CURRENT_USER\CLSID\MADOWN
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\MADOWN
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\AVPsys
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=um.exe
shell\open\Command=um.exe
SOLUTION
NOTES:
Trend customers:
Keep your pattern and scan engine files updated. Trend Micro antivirus software can clean or remove most types of computer threats. Malware, though, such as Trojans, scripts, overwriting viruses and joke programs which are identified as uncleanable, should simply be deleted.
All Internet users:
- Use HouseCall - the Trend Micro online threat scanner to check for malware that may already be on your PC.
- Catch malware/grayware before they affect your PC or network. Secure your Web world with Trend Micro products that offer the best anti-threat and content security solutions for home users, corporate users, and ISPs. Go here for more information on Trend Micro products that fit your needs.
Did this description help? Tell us how we did.