Stealth_boot

Classification

Category :

Malware

Type :

Virus

Aliases :

Stealth_boot, Nops, AMSE, PMBS, STELBOO, STEALTH_C, STEALTH_B. KOH

Summary

Members of the Stealth_boot family are pretty normal boot sector viruses with stealth capability. However, several of the variants of this virus are quite common all over the world.

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

Stealth_boot can infect a computer's hard disk only if the computer is booted from an infected diskette, in which case the virus infects the hard disk's Master Boot Record. The virus goes resident in memory the next time the computer is booted from the hard disk. Once in memory, Stealth_boot infects all non-write protected diskettes used in the computer.The stealth routines of the virus hide the infection, making infected boot sectors look clean as long as the virus is Resident, in memory. The virus code is visible after booting from a clean floppy.There are 13 different variants of this virus known (May 1996). The most common variants of this virus do nothing except spread. Stealth_boot.c is especially common all over the world.The Stealth_boot.KOH variants of this virus include an encryption system, which encrypts the hard drive with strong encryption if so wished by the user of the machine. These variants contain dangerous programming errors.The original source code of this virus has been published in a book, which explains the commoness of this virus.