W32.Opaserv.G.Worm

W32.Opaserv.G.Worm is a variant of W32.Opaserv.Worm. It is a network-aware worm that spreads across open network shares. It copies itself to the remote computer as the file Marco!.scr. It is compressed using PECompact.

This worm attempts to download updates from www.gwmnet.com.br, although the site may already have been shut down. Indicators of infection include:

• The existence of the files Mane!!.dat, FDP!!!!.dat, or Gay.ini in the root of drive C. This indicates a local infection (that is, the worm was executed on the local computer).
• The existence of the Gay.ini file in the root of drive C. This may indicate a remote infection (that is, the computer was infected by a remote host).
• The registry key HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\Current Version\Run contains the string value cronos or Cuzao!Old, which is set to C:\WINDOWS\marco!.scr.

NOTES:

• When the worm runs on Windows 95/98/Me-based computers, the worm can spread to other Windows 95/98/Me/2000/NT/XP-based computers through open network shares, but the worm cannot run on Windows 2000/NT/XP.
• Definitions dated prior to October 30, 2002, may detect this threat as W32.Opaserv.Worm.

NOTE: If you are on a network, or have a full time connection to the Internet such as DSL or Cable modem, you must disconnect the computer from the network and the Internet before attempting to remove this worm. If you have shared files or folders, these must be disabled. When you have finished the removal procedure, if you decide to reenable file sharing, Symantec suggests that you do not share the root of drive C. Share specific folders instead. These shares must be password-protected with a secure password. Do not use a blank password.

Also, before doing so, if you are using Windows 95/98/Me, you must download and install the Microsoft patch from

http://www.microsoft.com/technet/security/bulletin/MS00-072.asp

Protection

• Initial Rapid Release version October 30, 2002
• Latest Rapid Release version March 3, 2008 revision 035
• Initial Daily Certified version October 30, 2002
• Latest Daily Certified version March 3, 2008 revision 037
• Initial Weekly Certified release date October 30, 2002

Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Threat Assessment

Wild

• Wild Level: Medium
• Number of Infections: More than 1000
• Number of Sites: More than 10
• Geographical Distribution: High
• Threat Containment: Easy
• Removal: Moderate

Damage

• Damage Level: Low

Distribution

• Distribution Level: Medium