Lets talk about detection of viruses and trojans and other malwares... Tell me who develops the Anti Virus or Firewall Programs ? ANswer is Developers . Who creates the viruses and trojans etc.. Answer again is Developer. Can a developer bypass the thoughts of other developer's thoughts? Answer is YES. Because that is why testers are there. So let me tell you one thing some of the anti-viruses are known for false detections of viruses/trojans etc. Why it is there? Because there are different ways of detecting a virus in a system. Some detects on the basis of behaviour and some on the basis of the definition or code (machine code -- these are fixed size viruses.). and some on the basis of the origin of the code. Now a days , anti-viruses are using behaviour + deefinition based detection , so there are always chances that your common program may be detected as virus. So, If you know that your program is clean but AV is showing warning. What you gonna do then? How much trust you will have in for other detections ? About forums and torrents, I must say I never gone through any of such where posts are being deleted because those are having trojans... only other users just alerts theothers by posting their reviews regarding the post.