Many hacks start with a spear-phishing attack, often aimed at the top of the corporate hierarchy.
How do I hack thee? Let me count the ways. Among others, I hack thee to the depth and breadth and height of a spear-phishing attack (apologies to Elizabeth Barrett Browning).
By now, you may be aware that many of the most devastating hacks that have occurred in recent history—the Democratic National Committee (DNC), Yahoo, the W-2 scam—have been launched from a base of information or access garnered by sending a poisoned email with tailored details to a specific individual, who then becomes the vector for the rest of the attack.