Classification

Category :

Malware

Type :

Worm

Aliases :

San

Summary

San is a worm written in Visual Basic Script.

Removal

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.

    Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note: You need administrative rights to change the settings.

Technical Details

Variant:San.A@m

The worm arrives in an infected message sent with Outlook Express. When it is viewed, by opening it or via preview pane, it first drops "loveday14-a.hta" to the Windows Startup directory in both Spanish and English versions of Windows.

When the system is restarted, "loveday14-a.hta" will be executed. Also the worm creates an infected "index.html" file to the Windows System directory.

Next it uses registry to replace the default signature of Outlook Express 5 with the "index.html" created above.

On that way every time when an infected user send an email message, the worm will embed its html code to this message.

Next the worm replaces the Internet Explorer start page point to a web page, that contains another worm VBS/Valentine.A@mm. These two worms download each other.

If the system date is 8thy, 14th, 23rd or 29th on each month, then VBS/Sun.A will destroy the infected system. It will delete all directories and their contents from the drive "C:".

In the place of the original directories, the worm creates a folder with the same name adding a string "happysanvalentin". On that way a directory with a name "My Documents" will become "My Documentshappysavalentin".

This worm has been available on a public web page in the Internet and it has been posted to several Usenet newsgroups. Even after the infected web page has been removed from the Internet, the worm is able to spread via Outlook Express.

This worm uses the same security vulnerability as JS/Kak.A@m. A fix and futher information about this vulnerability is available from Microsoft: https://www.microsoft.com/technet/security/bulletin/ms99-032.asp

Further information about JS/Kak.A@m is available at: https://www.F-Secure.com/v-descs/kak.shtml