ngrok is a legitimate reverse proxy tool that can create a secure tunnel to servers located behind firewalls or on local machines that do not have a public IP. ngrok has been leveraged by threat actors in several campaigns including use for lateral movement and data exfiltration.(Citation: Zdnet Ngrok September 2018)(Citation: FireEye Maze May 2020)(Citation: Cyware Ngrok May 2019)(Citation: MalwareBytes LazyScripter Feb 2021)