Classification

Category: Malware

Type: Trojan

Aliases: Email-Worm.Win32.VB.as, Worm.Gasop.B, W32.Berlity@mm, Email-Worm:W32/VB.as, Worm/VB.AS.11, W32/Gasop@MM

Summary


VB.AS, a variant of VB, is a Trojan. VB.AS collects email addresses and is used by spammers to send emails from infected computers. VB.AS modifies registry keys and shows fake error messages.

Removal


Automatic action

Based on the settings of your F-Secure security product, it will either automatically delete, quarantine or rename the detected program or file, or ask you for a desired action.

Knowledge Base

Find the latest advice in our Community Knowledge Base.

About the product

See the manual for your F-Secure product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details


Upon execution, VB.AS, detected as Email-Worm.Win32.VB.as, displays a fake message: "File Error: [number]".

It then creates copies of itself in the following folders as:

  • %Temp% - (usually C:\Documents and Settings\[user]\Local Settings\Temp\ )
    • Horror.vbe
    • LSASS.exe
    • Service.exe
    • SVCHOST.exe
    • Winword.exe
  • %SystemDrive% - (usually C:\ )
    • COMAND.com
    • Spiderman.exe

It also creates the following registry entries to automatically launch when Windows starts:

  • [HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run] AVPScaner "C:\Documents and Settings\[user]\Local Settings\Temp\"
  • [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run] HostNet Service "C:\Documents and Settings\[user]\Local Settings\Temp\"

Additional registry entry:

  • [HKEY_CURRENT_USER\Software\Microsoft\Symantecs\Ver] Ver " 50"

It also searches for possible email addresses from all htm files found on the harddrive. All gathered data will be saved in the registry as follows:

  • [HKEY_CURRENT_USER\SOFTWARE\Microsoft\Records\FileList] List of htm files scanned for email addresses
  • [HKEY_CURRENT_USER\SOFTWARE\Microsoft\Records\AdressList] List of email addresses gathered
  • [HKEY_CURRENT_USER\SOFTWARE\Microsoft\Records\Names] List of gathered names from the email addresses (ex. 'myname@' from myname@domain.com)
  • [HKEY_CURRENT_USER\SOFTWARE\Microsoft\Records\Servers] List of gathered domain name the email addresses (ex. 'domain.com from myname@domain.com)
  • [HKEY_CURRENT_USER\SOFTWARE\Microsoft\Records\AdressAlList] List of all possible combination of email addresses based from the gathered names and domains
  • [HKEY_CURRENT_USER\SOFTWARE\Microsoft\Records\Activar] Indicates that the malware is active
  • [HKEY_CURRENT_USER\SOFTWARE\Microsoft\Records\Scaneado] Indicates that the malware has performed scan

Notes:

  • %Temp% - usually C:\Documents and Settings\[user]\Local Settings\Temp\
  • %SystemDrive% - usually C:\
  • [user] - is the current user

Description Created: 2006-10-04 08:15:33.0

Description Last Modified: 2006-10-04 16:06:56.0