Called office, came up on Caller ID as "Bank of America"; however, it's only 8:13 in CA so I hardly think B of A would be calling a business on the east coast at that hour (but then again it's probably a spoofed number), PLUS it came in our 4th line so I knew it wasn't a call for us. I answered but didn't say anything. They hung up, also without saying anything, after about 20 seconds. I can GUARANTEE if I'd answered with co name they would've hung up in my ear.
Caller ID is obsolete. With a computer, high speed internet, voip & a few dollars in software, a foreign criminal can make caller ID say whatever they want. As you did, always a good idea to NEVER give out personal information on a call you did not make. Bank called? Use a number from the back of the card, statement, or phone book.