Backhand is a polymorphic Word 97 macro virus which payload simulates the Y2K-problem.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
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.
Technical Details: Katrin Tocheva, F-SECURE