Because the Internet of Things is a major part of modern life, security threats are everywhere. Security incidents as well as the results of our many threat hunts have shown us that hundreds of millions of devices have been traumatized by attackers' malicious actions, made part of large botnets, or disrupted through malicious programs taking advantage of zero-day or one-day vulnerabilities.In order to reinforce detection and defensive capabilities against such IoT-ICS threats, we have deployed hundreds of automated threat hunting engines worldwide. In the past year, we have received and analyzed more than 45 TB of traffic, detected over 1.1 billion attacks from over 200 countries, and hunted 400 million plus suspicious IPs, 30 million plus suspicious domains, and over 1 million malicious files (RATs, trojans, worms, ransomware, and so on). Among those malicious files, more than 40% are unknown -- VirusTotal couldn't recognize them. We also found that more than 1.1 million devices may have been assimilated into botnets.This talk will share in detail how we built an automated large-scale threat hunting system, and give a deep look into the overall threat situation and trends from 6 hunting examples from the past year. We will share the benefits and responses to the threats we found, and the next steps for our threat hunting project.