One of the longest-running and more lethal malware strains has once again returned on the scene. Called Emotet, it started out as a simple banking Trojan when it was created in 2014 by a hacking group that goes by various names, including TA542, Mealybug and MummySpider. Emotet malware is back in the headlines and continues to be one of the most significant threats facing companies today. In this review for A10 Networks, I describe what it is and how it works and how to defend against it using a combination of network and security tools.