In the future if you are worried that your computer maybe infected download Malwarebytes and run this programme, (it is free and highly recommended) it will find any Trojans , (it is not an anti virus programme )also If you are not happy with AVG. Avast do an excellent free antivirus which I can recommend, I personally like it better that AVG which I found slowed my computer down. As stated the message says "in danger of" does not state is infected probably a pop up trying to sell you an antivirus or something similar.