I had a call from a 'Jennifer Thomas' in accented English, who asked to be transferred to a high executive in another branch of the company. When I told her his name didn't ring a bell, she asked me if I had access to our company's global directory to give her his direct line. I told her that I was sure if she needed someone of that level, she would have his assistant's number.
These calls are probably spear-phishing attempts, the caller wants emails of excecutives so other criminals can send emails with malware-infested attachments, the goal being to get into the company network to install information-stealing information to steal from bank accounts, etc.
Called our university, asked the secretary for me and was told I was in a meeting. He then -- in a thick Indian accent -- asked if he could have my direct number. Refused to identify himself or his company. Glad I could so easily check things via this site.