Incoming call showed up as mobile number. Caller asked for me by name, wanting me to verify my account details for a Commonwealth Bank credit card due to a transaction over $1000 from overseas. Noisy background, Indian accent. I asked him to tell me what my card number was, he told me the first four digits (same for all Mastercards) but wouldn't tell me the last four. I hung up. He called back and I didn't pick up. There was no such transaction on credit card.