Misterious increase in playtime?

[.Leo.]

I just opened my Steam Profile, and found something really unexpected: 9.6 hours of Counter-Strike in the past two weeks..
The thing is, it's been months I don't play that game...
Is this some kind of error, or maybe someone got their hands on my account?

It's quite unlikely to be the latter, since my password is (or was, as I changed it) quite complex to guess; and I didn't give it to anyone, or write it anywhere but the login dialog..
Even my email account is different from the one I give to other people...

I'll have to think this is a matter of Steam / the program files..
I didn't play Counter-Strike, but I did play "Contition zero: Deleted scenes" Maybe it's something on the game failing to fully close its process, thus still registering playtime on Steam as Counter-Strike, until I closed Steam, 9 hours later? When I logged out, I didn't get a dialog telling me to close any game...

Anyway, just in case I changed my password :P


EDIT: I just noticed I should have posted this in "Help and Tips" D: sorry for this