VBS.Solved

SUMMARY

VBS.Solved is a Visual Basic Scripting (VBS) virus that overwrites files. It sends 1000 email messages to two email addresses in Argentina.

Protection

• Virus Definitions (Intelligent Updater) February 27, 2001

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

Distribution

• Distribution Level: Low

TECHNICAL DETAILS

When VBS.Solved is run, it does the following:

1. It executes an email routine using Microsoft Outlook. The email routine sends the following email message to two fixed email addresses 1000 times:
   
   Subject:
   
   Recordatorio
   
   Message:
   
   Pezzani,pedazo de inuti,todavia no solucionaste nada . La guerra continua sin cuartel.Toma la iniciativa Charly.
   
   Attachment:
   
   C:WindowsExplorer.exe
   
2. After the email routine is executed, VBS.Solved inserts the following infected file in the C:Windows folder:
   
   NAV.exe .vbs
   
   NOTE: There are 74 spaces between NAV.exe and .vbs
   
3. VBS.Solved modifies the registry:
   • HKEY_CURRENT_USERSoftwareMicrosoft
     Internet ExplorerMainStart Page
     
     is modified to change the start page of Internet Explorer.
     
   • The value:
     
     Norton AntiVirus     NAV.exe   .vbs
     
     NOTE: There are 74 spaces between NAV.exe and .vbs
     
     is added to the key:
     
     HKEY_Local_MachineSOFTWAREMicrosoft
     WindowsCurrentVersionRun
     
     This causes the virus to run every time that the computer is started.
     
   • HKEY_CLASSES_ROOT.xls is deleted.
   • HKEY_CLASSES_ROOT.doc is deleted.
   • HKEY_CLASSES_ROOT.mdb is deleted.
   • HKEY_CURRENT_USERSoftwareMicrosoftWindows
     CurrentVersionInternet SettingsProxyEnable
     is set to "0".
   • HKEY_CURRENT_USERSoftwareMicrosoftWindows
     CurrentVersionInternet SettingsProxyServer
     is set to "0.0.0.0".
     
4. VBS.Solved then searches through all folders on all available drives for files with the following extensions, and attempts to infect them:
   • .btr
   • .pst
   • .xls
   • .mdb
   • .jpg
   • .pab
   • .wab
   • .dbx
     
5. VBS.Solved starts a loop that continuously checks to see if it is being deleted. When it sees that it has been deleted, VBS.Solved recreates itself with the same file name.

Due to a bug in the code, this virus does not run properly. If this is fixed, all the behavior mentioned previously would be observed.

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

To remove this worm:

1. Run LiveUpdate to make sure that you have the most recent virus definitions.
2. Start Norton AntiVirus (NAV), and run a full system scan, making sure that NAV is set to scan all files.
3. Delete any files detected as VBS.Solved.
4. If the virus has infected files, you will have to restore them from a clean backup or reinstall the software.