SweetOrange is an exploit kit that runs various exploits against the user's computer in order to probe for any vulnerabilities present in programs installed on the machine, or in the computer's operating system itself; if the exploit(s) are successful, then the user's machine may be compromised and exposed to further intrusion.
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.
As with most exploit kits, users may encounter SweetOrange on a compromised site on which an attacker has silently inserted the kit (much like a driveby download attack), or on malicious sites user has been forcibly redirected to from a compromised site.
For more about exploit kits, see Article: Exploit kits.