macbook pro keeps freezing

Fairly new 13" Macbook Pro keeps freezing-- bought it brand new two months ago.

I'll just be surfing the Internet or listening to music or whatever, and the whole thing will suddenly freeze without any warning (no lagging beforehand, etc.), and sometimes the screen will distort or flash/flicker a bit. The only way to fix it is a hard reset. It seems to be random as well-- sometimes the freezing happens after I've been using my laptop for less than an hour, and sometimes I can get it to run for hours without any problem. Additionally, aside from when it freezes up like this, I haven't had any other problems-- everything runs pretty smoothly.

The only things I've installed are pretty much the basics- Microsoft Office, Google Chrome, Evernote, Dropbox, etc. Uninstalled Chrome after hearing it had been giving others grief, but the problem persists. Have hardly used up any memory, so I don't think that's the problem. Ran an Apple Hardware Test and everything passed.

Any clue as to what the problem could be? Going to take it in to an Apple store this weekend but thought I might ask around first to see if anyone else had experienced this.

Thanks!