A net-worm is a type of worm that finds new host machines to infect by using network shares -a media (such as a hard drive or server) that can be accessed by multiple computers on a local area network (LAN), such as a company intranet. The net-worm will usually infect the share in order to subsequently infect every computer that accesses the share.
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.
In many cases, corporate computers and servers have a few open shares, making these networks particularly vulnerable and facilitating a net-worm's rapid spread through the network. In more sophisticated cases, net-worms may even contain a list of generic passwords to use in attacking password-protected shares.
Once transferred to another host machine, some net-worms copy themselves to startup folders of different users on remote computers. In this case they can start every time a user is logged on to the machine.
A net-worm may also include a malicious payload, such as dropping keylogger program on the infected computer, or attempting to connect it to a remote server.
For more information about worms, see Article: Worms.