Scammers. Don't answer, hang up if you did, don't call them back, block the number, advise your provider, report the number. Unfortunately for the scammers they contacted a secure witpro location where all incoming calls are immediately traced prompting a visit to their location by a team of agents. No "spoof" caller ID number is going to protect them as this is 2016. Wakeup scammers and pack your bags. Gitmo II is open and there are immediate vacancies to fill. After all, Halliburton has to make a living too!