Starting with version 3.7 of WordPress, the standard install includes a feature to automatically upgrade WordPress for third level changes. That is, if you’re running version 3.7.1 and WordPress releases 3.7.2, WordPress will automatically upgrade. It will not automatically upgrade to 3.8.
There is a way to turn off the automatic upgrade. I recommend that you leave the automatic upgrade in place, but I can turn if off if you wish.