In the fall of 2013, a manager at a company that operates heating and cooling systems received an email from his IT department asking him to verify his Windows ID and password. Without thinking about it, he provided the information and went on with his day. What he did not know was that the email he answered was not from his IT department, but rather from hackers. Weeks later, by exploiting other vulnerabilities, those hackers had compromised one of that company’s clients and gained access to millions of credit card records. You know this as the “Target breach.”