I've been getting the same calls on the hour all day.  I called Apple and confirmed it's a scam.

Rec'd 3 calls; finally responded.  Half way thru conversation things sounded a bit fishy, causing me to ask how I could be sure the person I was talking to was from Apple.  "Attitude" changed immediately; very defensive - not in keeping with previous Apple experiences at all.  He ended up hanging up on me.  The "real" Apple confirmed my suspicions.

Same "support" crap, 8:35AM Pacific.

Got a message twice about security breach in iCloud. Should call back 888-251-3172. I thought already it is a scam call.

Same message as above callers.  Called twice this morning starting at 7:58 am.  Recognized it as a scam and didn't answer!