It finally happened. The power grid went down, affecting hundreds of thousands of people, and the cause was at least in part computer malware. Some people had been warning about this for years.Maybe you didn\u2019t hear about it. The outage occurred in Ukraine, after all. But even though the incident didn\u2019t get a lot of attention here, it\u2019s still significant. And now that I\u2019ve called your attention to it, you might be wondering how this could have happened. Aren\u2019t our power grids \u201cair gapped\u201d from the Internet? Well, not exactly.When I say that, I\u2019m talking about the U.S. I don\u2019t know how things are done in Ukraine, but I have worked in the U.S. power sector and know something about the security policies and procedures here.The good news is that the power grid systems I\u2019ve seen are among the tightest, best-configured systems I\u2019ve ever encountered. The networks are set up to allow communications between computers using protocols that are expressly required for their missions. Any communication or protocol that isn\u2019t permitted in advance is dropped at the network access control level, and the security operators are alerted. I\u2019m sure there are exceptions to this in the sector, but that kind of tight configuration is the norm in the systems I\u2019ve seen.[ ALSO ON CSO: Russian group suspected to be linked to Ukraine power station cyberattack ]What\u2019s more, the back-end systems that actually connect to power systems are highly specialized devices that do not run general-purpose operating systems. These systems tend to be fail-safe, so if the computerized control were to fail, power would still be delivered to customers.Access to these networks is as rigorously controlled as anything I\u2019ve ever witnessed. Multifactor authentication and physical controls are normal. Security is taken very seriously in the U.S. power sector. Compared to general-purpose computing environments, these systems are simply rock solid.Ah, but let\u2019s not forget my favorite security motto: There ain\u2019t a horse that can\u2019t be rode, and there ain\u2019t a man that can\u2019t be throwed. And there are some practices within the power industry that are less than ideal.The systems used in today\u2019s smart grid environments, at least in the data centers, tend to run the same general-purpose operating systems you find elsewhere. They are subject to all the same \u201cpatch Tuesday\u201d problems as any other general-purpose, commercial off-the-shelf systems. Many of these systems have removable media, so it\u2019s feasible for malicious software to move from one security realm to another, even when the networks are configured to restrict such traffic. What\u2019s more, because of the mission-critical nature of the systems, patch rollouts are usually meticulous and slow. That, of course, means the systems are exposed to known vulnerabilities longer than a laptop computer that automatically downloads and installs patches the moment they\u2019re available.So I\u2019m not surprised that a power grid could be impacted by malware. It\u2019s disappointing, but it\u2019s going to happen, and this certainly won\u2019t be the last time.Most analysts talk about the need for industrial control systems (ICS) operators to keep the bad guys out. Fair enough, but don\u2019t for a minute think those ICS folk will be perfectly successful. Power suppliers\u2019 ICS teams need to be prepared for failures and have in place industrial-strength incident response planning and preparation. I\u2019ve seen some that do this very well, but the ICS world is quite new to incident response (at least, of the computer security variety). There is still plenty of work to be done, but at least ICS operators know, all too well, that they have to plan and drill for emergencies.With more than 20 years in the information security field, Kenneth van Wyk has worked at Carnegie Mellon University's CERT\/CC, the U.S. Deptartment of Defense, Para-Protect and others. He has published two books on information security and is working on a third. He is the president and principal consultant at KRvW Associates LLC in Alexandria, Va.