Please explain

Yesterday I installed a software called vRoute(I’m quite sure it’s safe). As soon as I got it down to my computer I ran a little scan of it and found no virus. I installed it and used it for a few minutes and then turned of the computer. When I tried to open it today there was a trojan in it?!? It was put away, no harm done. So I uninstalled vRoute and scanned the file including the installer again, no virus, I installed the program and the trojan is there?!
How is that possible? It happens with one other program as well.

I would really appreciate if someone with knowledge could clear this up for me.

Take care

The scanning engine isn’t always able to scan inside an installer. (If I’m understanding your problem correctly) So there could very well be a dangerous file packed inside and you wouldn’t know it until you install the software.

However, you can submit the questionable file to VirusTotal and see if all those other scanners agree that the file is harmful.

If it looks like a false positive detection, submit the file to Comodo Malware Analysis and they’ll fix it.

Okey, thank you