Not sure what you mean to send a trusted link ,, a link to what .. but here is a link to a Trojan remover that works good , I have used it for years and if you use the comprehensive search it can find the problem , the quick search may not find it right off .
worms ,viruses, malware , trojan horses , rootkits all with many variations , it is literally impossible for any one program to catch them all , even corporations use layers of protection even using portals where you use a password protected login in to a web site portal then use a different password/username to login into other servers on other layers of network .
Some trojans will use your cpu and memory in combination with other computers on the web , could be hundreds of them all together to create a high power hacking system that is nearly impossible to track the original source ,,
Google the Stuxnet virus and get a glimpse of what can be done with the right code . It takes a program designed specifically for Trojans to get the hard to get ones , the programs that are all-in-one programs are more for getting the consumer to think they are totally covered , but can't do it all , it be like a scaled down version of various progs , combined , So the sad thing is that no matter what OS you use or virus prog you use there will always be something that can attach itself to your system, if you search the web often the high risk there is , which is why I use multiple progs and learn the more intensive way they can be used as the simple scans may not catch all that it can ,, Microsoft often buys software companies and adds it to their products . Windows 7 Professional has a very good firewall . in the snap-in category , it is about the same level as a linux , but it takes a bit of study to learn how to configure it properly ,, as it is deep in the system in computer management