This is not a virus. Actually, the typical support query goes like this:
Question: I found a file called "nul" in my root directory. I can not access or delete it. Later I found it existed in each and every directory! This has to be a virus!
Answer: How did you find it? With which program?
Try locating in a same manner files with names such as "lpt1", "prn", "com1", "clock$" and you will see that they too exist in every directory and can not be accessed or deleted. This is normal and is a feature of DOS.
These are virtual names for system devices: prn for printer, nul for null port, clock$ for CMOS memory etc. Ignore them.
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.
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