W32.Bobax!gen

SUMMARY

W32.Bobax!gen is a generic detection that detects variants of W32.Bobax family of worms.

Protection

• Virus Definitions (LiveUpdate™ Weekly) September 11, 2005
• Virus Definitions (Intelligent Updater) September 9, 2005

Threat Assessment

Wild

• Wild Level: Medium
• Number of Infections: 50 - 999
• Number of Sites: More than 10
• Geographical Distribution: Medium
• Threat Containment: Moderate
• Removal: Moderate

Damage

• Damage Level: Medium
• Large Scale E-mailing: May mass mail itself to addresses gathered from the compromised computer

Distribution

• Distribution Level: Medium
• Subject of Email: Varies
• Name of Attachment: Varies
• Ports: TCP 445. May listen on other ports as well

TECHNICAL DETAILS

W32.Bobax is a worm that may spread by:

• Mass mailing itself to addresses gathered from the compromised computer.
  
• Exploiting Microsoft Windows vulnerabilities.
  
  For example, it may:
  Exploit the Microsoft Windows Plug and Play Buffer Overflow Vulnerability (as described in Microsoft Security Bulletin MS05-039)
  Exploit the Microsoft Windows LSASS Buffer Overrun Vulnerability (described in Microsoft Security Bulletin MS04-011)
  
• Infecting files that it finds on the compromised system.

Recommendations

Symantec Security Response encourages all users and administrators to adhere to the following basic security "best practices":

• Turn off and remove unneeded services. By default, many operating systems install auxiliary services that are not critical, such as an FTP server, telnet, and a Web server. These services are avenues of attack. If they are removed, blended threats have less avenues of attack and you have fewer services to maintain through patch updates.
• If a blended threat exploits one or more network services, disable, or block access to, those services until a patch is applied.
• Always keep your patch levels up-to-date, especially on computers that host public services and are accessible through the firewall, such as HTTP, FTP, mail, and DNS services (for example, all Windows-based computers should have the current Service Pack installed.). Additionally, please apply any security updates that are mentioned in this writeup, in trusted Security Bulletins, or on vendor Web sites.
• Enforce a password policy. Complex passwords make it difficult to crack password files on compromised computers. This helps to prevent or limit damage when a computer is compromised.
• Configure your email server to block or remove email that contains file attachments that are commonly used to spread viruses, such as .vbs, .bat, .exe, .pif and .scr files.
• Isolate infected computers quickly to prevent further compromising your organization. Perform a forensic analysis and restore the computers using trusted media.
• Train employees not to open attachments unless they are expecting them. Also, do not execute software that is downloaded from the Internet unless it has been scanned for viruses. Simply visiting a compromised Web site can cause infection if certain browser vulnerabilities are not patched.

REMOVAL

Symantec Security Response recommends that any files detected as W32.Bobax!gen are submitted to Symantec Security Response. For instructions on how to do this, read the following documents:

• Norton AntiVirus: How to submit a file to Symantec Security Response using Scan and Deliver
• Symantec AntiVirus Corporate Edition and Norton AntiVirus Corporate Edition: How to submit a file to Symantec Security Response using Scan and Deliver