Question abotu Trojans and Trojan Scanners

Here's a thread with some recent posts regarding this rather unique online scanner. (Edit: Well, I see that you actually posted in that thread. See Paul's opinion near the end of the thread for the most reliable opinion on this scanner.)

https://www.wilderssecurity.com/showthread.php?t=13929

If it's a RAT (remote access trojan) it may very well trigger an alert from a resident software firewall running on your PC (depending upon firewall configuration, of course).

Well, you need to be careful in your software configuration to make sure you don't accidentally allow something by mistake, but, if you generally don't download any files, don't open any email that contain file attachments, don't expose any exploitable services to the Internet (i.e. allowing unsolicited connections in from the Internet), do keep current on all OS and browser patches, and do use tight security settings when you browse Internet websites, then your chance of getting Trojans is very greatly reduced.

In addition to the online Trojan scanner you linked above, you could also run a couple online AV scanners, some of which are not bad at Trojan detection. (See our Free Services page.)

Also, you could run an evaluation copy of either Trojan Hunter or TDS-3 to fully test your systems current state regarding Trojans.