Utility companies received phone calls allegedly from “Microsoft Server Department” warning of infected PCs. Social engineers often send emails, hoping for a bite, or a link to clicked or a download to be opened. Social engineers also place calls, and in the guise of needing help or pretending to be someone in authority, can often persuade a person to divulge too much information about a company. However, as was seen twice at DefCon, social engineering is lethal to corporate America. US-CERT: “Need for continued vigilance for everyone involved in critical infrastructure, particularly regarding recognition of social engineering attempts””]