https://arstechnica.com/information-technology/2019/09/worlds-most-destructive-botnet-returns-with-stolen-passwords-and-email-in-tow/

If you've noticed an uptick of spam that addresses you by name or quotes real emails you've sent or received in the past, you can probably blame Emotet. It's one of the world's most costly and destructive botnets—and it just returned from a four-month hiatus.

Emotet started out as a means for spreading a bank-fraud trojan, but over the years it morphed into a platform-for-hire that also spreads the increasingly powerful TrickBot trojan and Ryuk ransomware, both of which burrow deep into infected networks to maximize the damage they do. A post published on Tuesday by researchers from Cisco's Talos security team helps explain how Emotet continues to threaten so many of its targets.