According to press reports, a water utility’s SCADA network was hacked. The attacker turned a pump on and off too much, resulting in physical damage to the pump. This is an extremely significant incident, for three reasons:

• The attack actually happened.
• Ordinary, off-the-shelf hacking tools were used, rather than something custom like Stuxnet
• Physical damage resulted

Arguably, the first point is the most important one. For years, security specialists have been warning that something like this could happen. Although more and more people have started to believe it, we still hear all of the usual reassuring noises—the hackers don’t know enough, we have defenses, there are other safeguards, etc. That debate is now over: we have an existence proof. All future debate has to start from this fact: the threat is real. We can argue over magnitude, but not over the possibility.

The second noteworth point is that it didn’t take the cyberwarfare unit of a major nation-state to break in. (“Nation-state”? Are there that many city-states around today that we need to describe which kind of “state” we’re worried about? Or is the qualifier intended to distinguish it from nations that aren’t states?) Reports point to ordinary vulnerabilites in standard web software.

Finally, the attack caused physical damage to a water pump. It’s not enough to wipe the disk of the compromised computer and restore from backups; instead, you have to acquire and install new hardware. This is the really scary part about attacks on SCADA systems: the defenders almost certainly have less replacement hardware than they would need in event of a large-scale, focused, malicious attack.

Exactly what happened here is not yet completely clear. The implications, though, are scary.