Backhand

Classification

Malware

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Backhand, Backhand.A

Summary

Backhand is a polymorphic Word 97 macro virus which payload simulates the Y2K-problem.

Removal

Automatic action

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.

Suspect a file is incorrectly detected (a False Positive)?

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 detection database 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.

Find out more

Knowledge Base

Find the latest advice in our Community Knowledge Base.

User Guide

See the user guide for your 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

The virus replicates when an infected document is opened, closed or a new one is created.

Backhand.A first disables the build-in macro virus protection. After that it drops its code in a file "sysboot.bin" to the root of "C:" drive and uses it to infect global template and documents.

When infects documents the virus change some of its subroutine names with random ones.

The virus contains a few payloads. First of them activates when the day of the month is 13. Than it saves the active document with a random password and shows a message:

 Your document has been corrupted because of a bug in Word!
 Call Microsoft Customer Support, they can help you. When you
 call, tell them this Bug-ID Code (don't forget it!)

If the day is also Friday then Backhand.A shows another message:


Have A Nice Day!

It's Friday 13th! This is my lucky day, I hope it's

yours too!

The last payload activates in year 2000 or later when Backhand.A change the system date to January 1st 1980.