This virus does not really swap anything, so the alias name is a bit misleading. This boot virus from Israel is unusual in that it does not store the original boot sector anywhere, but instead it just overwrites the original boot sector with a short piece of code to load the rest of the virus, which is stored on one of the last sectors on track 39. A similar method is used by the Alameda virus.
When this virus activates it is said to produce a display of falling letters on the screen - similar to the Cascade virus, but I have not seen this effect yet.
The VSAFE program belonging to Microsoft Antivirus is known to cause false Falling Letters alarms in other antivirus programs. If unsure, delete VSAFE program, reboot and retry.
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 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.