Classification

Category :

Malware

Type :

Worm

Aliases :

Tune

Summary

VBS/Tune is an email worm written in VBScript language that propagates when the receiver double-clicks on the attachment.

Programs written in VBScript operate only under Windows 98 and Windows 2000 (unless Windows Scripting Host has been installed).

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

VBS/Tune does not work at all under default Windows 95 and Windows NT 4.0 installations. However, it does work under 95 and NT 4 provided that other supporting software (such as Microsoft Internet Explorer v5.x) has been installed.

Tune was found in December 1999. This worm uses similar method to spread like Melissa and Freelink. The mass-mailing part uses Outlook, while mIRC and Pirch are also used to spread the worm.

When Tune is executed, it copies itself to three different directories - Windows, Windows' system and temporary directories. After that it changes the registry in a such way that it will be executed when the system is restarted:

HKCU\Software\Microsoft\Windows\CurrentVersion\Run\ScanRegistry

 HKCU\Software\Microsoft\Windows\CurrentVersion\Run\TaskMonitor
 

Then it copies itself to the root of each fixed and network drive.

The worm uses Outlook application to send itself as an attachment to all recipients in every address book. The email message that VBS/Tune sends contains the following subject and body:

Subject: Please Read
 Body:

Hey, you really need to check out this attached fileI sent you...please check it out as soon as possible.
 

The worm checks the registry if the mailing has been already done and if yes, then it does not do mass-mail itself again.

VBS/Tune does not remove the sent mail from "Sent Items" folder. On that way the mass-mailing is visible for the user.

The worm also spreads via mIRC and Pirch chat clients. It searchs for "C:\MIRC" and "C:\Pirch98" directories. If Tune founds either one, it will overwite the "script.ini" and "events.ini" respectively.

After that both IRC clients will automatically spread the worm when the user enters IRC chat channels.