Any malware detectors for os X? High fan speeds that I'm not used to seeing

This may be a dumb question, an this may not be the right place to ask, but is it worth it to get some kind of malware/virus detectors for OS X?

I run parallels for my work, with windows 7 as the OS. I noticed, especially when using Parallels, that the fans eventually run high rpm's: the CUP fan around 1700 or so, maybe a bit higher at times. Eventually at always goes up when I'm using it.

And just now the optical and HD fans were over 1000 -- around 1100 or so for the optical fan, and 1300 for the HD fan.

The power supply 2 temp also changes, but that may be normal, since I don't know how that works.

I have istat pro to monitor all this.

This doesn't seem to have happened before, and i was just wondering if maybe I've got some kind of virus that causes this.

Now I'm not an expert when it comes to this stuff, and I know that the fans will run higher when you use the machine, but it just seems to me that it could be possible that something else would be causing this, something that shouldn't be there and makes things work more than they should. When I just have the machine on and using, say, Safari and nothing else, the CPU fan RPM is around 939-941 (which I guess is the normal kind of 'idle' speed).

in my iStat pro, even with windows running, the CPU use by the User is 10% or so and the "System" portion of it is maybe around 4 percent or so, with the idle portion being somewhere around 86 to 88 percent. I just thought that with that much of the CUP being idle that it wouldn't be taking the machine that much to cause the fans (most notably the CUP fan) to run so high.

Even when I shut down paralells the fan still runs kind of high (around 1300-1400 rpm or so).

So I'm just wondering, since as I said this doesn't seem to have happened before; and I'm not sure if I had this problem before I went to Yosemite from Snow Leopard.

I'd be happy to post a screen shot of my istat pro, but I don't know how to do that or if it's even possible.

Has anyone else experienced this?