Many organizations that run industrial control systems strive to isolate them from the Internet, but sometimes forget to disallow Domain Name System (DNS) traffic, which provides a stealthy way for malware to exfiltrate data.
Sometimes referred to as supervisory control and data acquisition (SCADA) systems, industrial control systems (ICS) are notoriously insecure. Not only is their firmware full of flaws, but the communication protocols many of them use lack authentication or encryption.
