Trojan:W32/Fakealert is a large group of malware that either tricks the user into installing other malicious programs - typically rogue antivirus software - onto the affected machine, or silently downloads and installs such programs itself.
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.
Most Fakealert variants will either silently install themselves on the user's machine by exploiting a vulnerability in the system or an installed application; or will use a social engineering ploy to trick the user into installing it themselves (usually by pretending to be a desired program, such as a codec, a video or a game).
Once present on the system, the Fakealert malware will display a fraudulent notification or alert designed to alarm users into believing that their system is infected with spyware. The user is then either encouraged to purchase these rogue security applications, or the program is silently downloaded and installed on the affected machine.
A representative example of how a Fakealert malware behaves is: