FrostWire installer downloaded directly from our website www.frostwire.com or via automatic update doesn't contain any trojans/viruses for sure. We have never seen FrostWire itself being marked. We have seen a file called OCSetupHlp.dll in our installer to be market as Trojan sometimes.
This file comes form the offers for additional software we show before each installation to support the future development of the project.
That's how we are able to pay for all the server and developer costs and still provide you with a free quality product with no ads. You can skip the offers if you choose to. None of the additional software contains any viruses either - we do allow only the once we've checked.
The notifications are mostly due to the antivirus being a bit overzealous and we are working on having the respective companies to correct them as soon as they appear.