You have to provide your Mac user password in order to run MacScan. The menu is simple and easy to understand. It is in a little window with a number of options at the top. There is: Status, Scan, Web Files and Info. I hit scan and have the option to run either a Quick Scan (Home folder of a selected user), a Full Scan (all files on the computer) or a Custom Scan (you get to choose which files are scanned). I choose Full Scan and let it run.
It makes the fan start up on my MacBook, but otherwise it lets me carry on with my work as usual with no interruptions.
It can take a while to run, almost an hour, depending on how many files you have on your computer. MacScan has a blacklist of over 8000 cookies (according to their website). It tracks down the spyware on your computer and gives you the option to get rid of it or not once the scan is complete. I'm not sure who would choose to keep it, but I guess if you want to the choice is yours.
Also, MacScan can be scheduled to run at certain times. If you don't want to run it manually every week or so, just schedule it to do it for you. It's very handy.
