They are a very rude financial firm trying to get new clients. They repeatedly call my boss (who doesn't use voicemail) and want him to call them back. When I ask what it is regarding, they say it's private. When I tell them he likely won't call back without a topic - they hang up.
Same thing: "This is Ted Lellos at National (mumble). Give me a call. 202-825-3500." He's a registered securities dealer (CRD #1955971) with National Securities Corporation, 145 North Franklin Turnpike, Suite 101, Ramsey, NJ 07446 (CRD# 7569).