Modern anti-virus programs can detect a wide range of potentially dangerous programs. This normally goes far beyond traditional viruses and worms and often includes heuristic alerts, which basically means that you can get alerts when an anti-virus program "thinks it could be ..."
In many cases, users download a keylogger, password cracker, remote access software, PC monitoring software or similar applications, not realizing that these programs actually could be considered a trojan by your anti-virus software.
These programs are usually detected because they could violate your privacy if they were installed without your knowledge!
If anti-virus software wouldn't warn you, anybody could trick you into installing such software, or install it on your computer without your consent.
In addition, many anti-virus programs will warn you about "hook" related dangers. A "hook" is a way for an application to capture keyboard input. This is often used for hotkeys (press some keyboard keys to start the app, or make it do something) and a common programming technique. Unfortunately the same type of technique is used by many keyloggers - they use the "hook" method to capture your keystrokes, instead of keyboard commands.
If you downloaded the software from us, you can be sure that we verify all products and test them before we include them in our catalog, and we have never had a single incident of a "real" virus or trojan since 1997. So if you run into any "hook" related warnings, it is very likely to be a regular feature of the software that is misinterpreted by your anti-virus software. You may want to check with the anti-virus vendor or the software author if you have concerns.
Make sure that your anti-virus signatures have been updated today!
Before you panic, get a second opinion to make sure it's not a false positive. You can use free online scans, they are available from several commercial anti-virus vendors and allow you to upload and scan a file online.
Free online scanners:
Recommended: VirusTotal (scans a file with 30+ antivirus products)