When will my PLC support Mirai? The security economics of large-scale attacks against Internet-connected ICS devices Michael Dodson Alastair R. Beresford Daniel R. Thomas University of Cambridge University of Cambridge University of Strathclyde Email:
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[email protected] Abstract—For nearly a decade, security researchers have high- The Internet-connected ICS device population shares many lighted the grave risk presented by Internet-connected Industrial characteristics with other populations that have attracted large- Control Systems (ICS). Predictions of targeted and indiscriminate scale criminal activity, such as size, stability, and lack of long- attacks have yet to materialise despite continued growth of a vulnerable population of devices. We investigate the missing term support. The population is approaching 100 000 devices, attacks against ICS, focusing on large-scale attacks enabled of which we tracked approximately 10% over four years. by Internet-connected populations. We fingerprint and track We find that over 60% of tracked devices are continuously more than 10 000 devices over four years to confirm that the connected at the same IP address for years, fewer than 25% population is growing, continuously-connected, and unpatched. ever receive a software update, and that the overall population We also track 150 000 botnet hosts, monitor 120 global ICS honeypots, and sift 70 million underground forum posts to show is growing with the addition of the newest hardware and that the cybercrime community has little competence or interest software from major manufacturers. in the ICS domain. Attackers may be dissuaded by the high cost Despite these vulnerabilities, we show that the actual risk of entry, the fragmented ICS population, and limited onboard to ICS devices is low.