Home installation Lounge forum: ActMon - where did it come from and have I got rid of it.

Today I ran a deep scan using ZoneAlarm Pro firewall spyware scanner. I do a weekly full Norton Scan, last one was four days ago, and hadn't done a full Zonelabs scan for a while. I did a quick ZoneAlarm scan yesterday after a friend used the pc and it found nothing.
Today it found something called ActMon which it described as a keylogger and password stealer and said it was password protected and e mailed my details to someone in stealth mode - at which point I got scared - but Zonealarms assured me it could and would get rid of it for me. So I told it to delete.
First I looked at the location. It was in a downloaded object for a very reputable and wellknown pc game. I already have this object in my game but was creating a back up file. No ActMon has ever been found before on my pc, so I guess - in my amateur way - that it picked that file at random to hide in. Anyway ZoneAlarm has deleted the affected file from the pc, but I don't know what it did about the registry entries.
I looked up ActMon on the net and it seems to be a legit program for spying on employees for example to see what they are up to, But in the hands of the wrong person it can be used to steal data. I have no idea how it got on my pc or when. I would like to feel reassured that ZoneAlarm has dealt with it. I have to admit that I allowed a friend to use my pc yesterday unsupervised while I had to go to work because her pc is broken and she needed to download a bootdisk from Packard Bell. After I had left for work she might have gone surfing on my administrator account with the firewall security at minimum because she likes astrology sites. It might be something she picked up,but I have also been getting lots of spam and have been notified on several occasions by my isp of spam e mails with trojans that have been intercepted en route to my pc.
As Zonelabs are a reputable company and this spyware does not appear to be a newcomer on the scene do you think I can be confident that it has been dealt with successfully?