The Mirai botnet, a collection of hijacked gadgets whose cyberattack made much of the internet inaccessible in parts of the US and beyond a year ago, previewed a dreary future of zombie connected-device armies run amuck. But in some ways, Mirai was relatively simple—especially compared to a new botnet that's brewing. While Mirai caused widespread outages, it impacted IP cameras and internet routers by simply exploiting their weak or default passwords.