From Bank Info Security:

Today’s spear-phishing campaigns are localized, small and can slip through typical spam filters. As a result, detection practices have to evolve, says researcher Gary Warner of the University of Alabama at Birmingham. “The important thing to realize is that the average attacker is going to keep coming back until that institution puts in an effective countermeasure,” says Warner, director of research for computer forensics at the university. “So how do we learn from the past incidents? We have to log the data, analyze it and recognize the indicators.”