W97M.Maike

SUMMARY

W97M.Maike infects Microsoft Word 97/2000 documents when you open or close them.

Protection

• Virus Definitions (LiveUpdate™ Weekly) August 21, 2002
• Virus Definitions (Intelligent Updater) August 19, 2002

Threat Assessment

Wild

• Wild Level: Low
• Number of Infections: 0 - 49
• Number of Sites: 0 - 2
• Geographical Distribution: Low
• Threat Containment: Easy
• Removal: Easy

Damage

• Damage Level: Low
• Payload Trigger: On the 1st, 14th and 28th of the month, changes registered user, organization and product ID.
• Modifies Files: Adds macro virus code to MS Word documents.
• Compromises Security Settings: Changes MS Word 2000 security settings to lowest level.

Distribution

• Distribution Level: Low

TECHNICAL DETAILS

The Word Basic macro virus infects documents by way of the Normal.dot template when a document is opened, closed, or saved. It also infects Normal.dot when Visual Basic code is viewed (Alt+F11) or macros are displayed (Alt+F8).

Macro code is exported to and imported from the %system%Maike.sys file.

NOTE: %system% is a variable. The virus locates the System folder and copies itself to that location. By default this is C:WindowsSystem (Windows 95/98/Me), C:WinntSystem32 (Windows NT/2000), or C:WindowsSystem32 (Windows XP).

The macro will not infect documents on the 1st, 14th, or 28th of the month, but it will change the registry so that when the registered owner and organization are displayed, they appear as:

Maike, you are the most beautiful girl in the world.

It does this by making several changes to the registry key

HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersion

• The value data of
  
  RegisteredOwner
  
  is changed to
  
  Maike you are
  
• The value data of
  
  RegisteredOrganization
  
  is changed to
  
  the most beautiful
  
• The value data of
  
  ProductId
  
  is changed to
  
  girl in the world

You can reset these values to their original settings.

In addition, when Word 2000 is installed, the macro resets security to the lowest level by setting the registry key

HKEY_CURRENT_USERSoftwareMicrosoftOffice9.0WordSecurityLevel

to a value of 1.

The virus creates the key if it does not exist.

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

NOTE: These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines.

1. Update the virus definitions, run a full system scan, and repair all files that are detected as W97M.Maike.
2. (Optional) Restore the original information to the registry key that the virus changed,
3. If you are using Microsoft Word 2000, reset the security level.
   

For details on how to do this, read the following instructions.

To scan for and repair the infected files:

1. Obtain the most recent virus definitions. There are two ways to do this:
   • Run LiveUpdate, which is the easiest way to obtain virus definitions. These virus definitions have undergone full quality assurance testing by Symantec Security Response and are posted to the LiveUpdate servers one time each week (usually Wednesdays) unless there is a major virus outbreak. To determine whether definitions for this threat are available by LiveUpdate, look at the Virus Definitions (LiveUpdate) line at the top of this write-up.
   • Download the definitions using the Intelligent Updater. Intelligent Updater virus definitions have undergone full quality assurance testing by Symantec Security Response. They are posted on U.S. business days (Monday through Friday). They must be downloaded from the Symantec Security Response Web site and installed manually. To determine whether definitions for this threat are available by the Intelligent Updater, look at the Virus Definitions (Intelligent Updater) line at the top of this write-up.
     
     Intelligent Updater virus definitions are available here. For detailed instructions on how to download and install the Intelligent Updater virus definitions from the Symantec Security Response Web site, click here.
     
2. Start your Symantec antivirus software and make sure that it is configured to scan all files.
   • Norton AntiVirus Consumer products: Read the document How to configure Norton AntiVirus to scan all files.
   • Symantec Enterprise antivirus products: Read the document How to verify a Symantec Corporate antivirus product is set to scan All Files.
3. Run a full system scan.
4. If any files are detected as infected by W97M.Maike, click Repair.

To remove the value from the registry:

NOTE: This is optional, because the change to the registry key does not affect system functionality. If you have any questions about how to reset these values, contact your system administrator or a qualified computer consultant.

CAUTION: Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document How to make a backup of the Windows registry for instructions.

1. Click Start, and click Run. The Run dialog box appears.
2. Type regedit and then click OK. The Registry Editor opens.
3. Navigate to the key
   
   HKEY_LOCAL_MACHINESoftwareMicrosoftWindowsCurrentVersion
   
4. In the right pane, update the values
   
   RegisteredOwner
   RegisteredOrganization
   ProductId
   
   by double-clicking each in turn and re-entering the name of the registered owner, the registered organization, and the product ID for the copy of Windows that is installed on the computer.
5. Exit the Registry Editor.

To reset the Microsoft Word 2000 security level:

1. Click Tools.
2. Point to Macro.
3. Click Security.
4. Click the desired security level, and click OK.