W32.Myparty@mm

SUMMARY

W32.Myparty@mm is a mass-mailing email worm. This worm is capable of spreading itself only between January 25, 2002, and January 29, 2002. However, it remains active on infected computers after this period of time.

It has the following characteristics:

Subject: new photos from my party!
Message:
Hello!

My party... It was absolutely amazing!
I have attached my web page with new photos!
If you can please make color prints of my photos. Thanks!

Attachment: www.myparty.yahoo.com

The worm sends email to all contacts in the Windows address book and to email addresses that it finds in the Outlook Express inboxes and folders. In addition, the worm sends a message to the author so that the author can track the worm.

On Windows NT/2000/XP-based computers, the worm drops a backdoor Trojan that allows a hacker to control the system. Norton AntiVirus detects this as Backdoor.Myparty.

Finally, if the file name of the worm is Access.<any extension>, it may launch the Web browser to http:/ /www.disney.com. However, the worm does not contain code which can generate a file with the name Access.<any extension>, so it is highly unlikely that this will trigger.

Protection

• Virus Definitions (LiveUpdate™ Weekly) January 28, 2002
• Virus Definitions (Intelligent Updater) January 28, 2002

Threat Assessment

Wild

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

Damage

• Damage Level: Low
• Payload Trigger: January 25-29, 2002
• Large Scale E-mailing: Sends email to all contacts in your Windows address book, and to email addresses that if finds in the Outlook Express Inboxes and folders.

Distribution

• Distribution Level: High
• Subject of Email: new photos from my party!
• Name of Attachment: www.myparty.yahoo.com
• Size of Attachment: 29,696 bytes

TECHNICAL DETAILS

W32.Myparty@mm arrives as an email message with the following characteristics:

Subject: new photos from my party!
Message:
Hello!

My party... It was absolutely amazing!
I have attached my web page with new photos!
If you can please make color prints of my photos. Thanks!

Attachment: www.myparty.yahoo.com

When it is executed, the worm first checks the date. If the computer date is not between January 25-29, 2002, or if the keyboard settings are set to Russian, the worm copies itself to

C:RecycledF-<random digits>-<random digits>-<random digits>

and exits. Otherwise, the worm continues.

The worm next checks its own file name, and performs different actions depending on the file name or extension:

• If the file name is "Access," the worm attempts to launch the Web browser to http:/ /www.disney.com and exits. However, the worm does not contain code that can generate a file with the name Access.<any extension>, so it is highly unlikely that this will trigger.
• If the file name has a .com extension, the worm copies itself to one of the following locations:
  • C:Regctrl.exe (Windows NT/2000/XP)
  • C:RecycledRegctrl.exe (Windows 95/98/Me)
  and then executes the Regctrl.exe file.
• If the file name has the .exe extension (for example, Regctrl.exe), the worm begins its propagation routine:
  1. The worm searches the Windows address book that is used by Microsoft Outlook and Outlook Express; it also searches for email addresses in files with the .dbx extension in the Microsoft Outlook Express folder. (The .dbx files are Microsoft Outlook Express folders and inboxes.)
  2. The worm sends itself to these email addresses using its own SMTP engine. The worm uses the default SMTP server address that is configured on the computer. The From: address is set to your email address.
  3. On Windows NT/2000/XP-based computers, the worm creates a backdoor Trojan:
     
     %Windows%Profiles\%User_name%Start MenuProgramsStartupmsstask.exe
     
     or
     
     Documents and Settings\%User_name%Start MenuProgramsStartupmsstask.exe
     
     so that it is executed when you start Windows. This backdoor Trojan contacts a Web page at 209.151.250.170, which allows the author to have access to the computer. Depending on the contents of the Web page, the backdoor will perform different actions. This backdoor will be detected as Backdoor.Myparty by Norton AntiVirus.
     
     NOTES:
     • %Windows% is a variable. The worm locates the Windows folder (by default this is C:Windows or C:Winnt) and copies itself to that location.
     • %User_name% is a variable. The worm locates the name of the user who is currently logged on and uses that where indicated.

Finally, the worm sends a message to napster@gala.net, allowing the author to track how far the worm has spread.

If W32.Myparty@mm is currently active, the process can be identified by the following smiley face :-) in the Task List/Manager.

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

1. Run LiveUpdate to make sure that you have the most recent virus definitions.
2. Do one of the following, depending on your version of Windows:
   • Windows 95/98/Me/200/XP: Restart the computer in Safe mode. All Windows 32-bit operating systems except Windows NT can be restarted in Safe mode. Read the document for your operating system.
     • How to start Windows XP in Safe Mode.
     • How to start Windows 2000 in Safe mode.
     • How to restart Windows 9x or Windows Me in Safe Mode.
   • Windows NT: End task in the Msstask.exe process. To do this:
     1. Press Ctrl+Alt+Delete one time.
     2. Click Task Manager.
     3. Click the Processes tab.
     4. Click the "Image Name" column header two times to sort the processes alphabetically.
     5. Scroll through the list, and look for the following process:
        
        Msstask.exe
        
        CAUTION: This is not the same as Mstask.exe--note the single "s". Mstask.exe is a legitimate Microsoft process. Do not end that task.
        
     6. If you find the file--you will only find it if the process is currently running--click it and then click End Process.
     7. Close the Task Manager.
3. Start Norton AntiVirus (NAV), and make sure that NAV is configured to scan all files. For instructions on how to do this, read the document How to configure Norton AntiVirus to scan all files.
4. Run a full system scan.
5. Delete all files that are detected as W32.Myparty@mm or Backdoor.Myparty.