"hashes-3.4.2.php missing" Am I Hacked?

“The file containing hashes of all WordPress core files appears to be missing; modified core files will no longer be detected and a lot more suspicious strings will be detected“

I ran Exploit Scanner today for the first time in about a week and got this message, followed by hundreds of critical alerts, apparently triggered by this missing file. Site SEEMS to be OK, but I’m no expert.

Is this just a bug with 3.4.2, or what? What do I do about this?

Thanks for any help!