[beerandt]

To me, the biggest red flag is asking for any identifying info in a conversation they initiated, especially without them initially providing some sort of privledged information to you first.

Unfortunately, some banks do this. (I'm looking at you, U.S. Bank.)

It's like someone calling me and then asking me who they're speaking to. Really? You called me! (Assuming they're not returning a missed call, of course.)

If (someone claiming to be) a bank calls/texts you, (and it's not immediately after a declined transaction) you always hang up and call the number you already have for the bank.

Even if it is after a declined transaction, you still don't provide any info. If they ask if you attempted a $101.89 purchase at "big box store," you should simply respond yes/no, and provide no other info.

If you didn't attempt that transaction, they especially don't need to confirm any other info.