One of the greatest scams for hackers is also one of the best illustrations of how NOT to handle your emails. In many cases, a hacker may act as the CEO of a company and ask different departments for sensitive information (tax forms.) A company is breached not as a result of a diligent, intelligent hacker, but because of the employees not understanding how to handle sensitive information. If you believe this is too far-fetched to be real, here is the IRS specifically warning against these attacks. To defend yourself against these, just check with the actual person before you send sensitive information. If someone asks you to send them sensitive information, make 100% sure it is actually them.