Cybersecurity was in the news again this week as hackers released contact details of thousands of FBI and Homeland Security employees after claiming to have taken 200 GB of data from Department of Justice computers. But even as such breaches have started to feel almost routine, they are also taking a more troubling turn.

Imagine traffic being halted, subway trains going berserk, furnaces and cooling systems firing out of control, or worse yet, a nuclear power plant melting down — all due to a cyberattack. This is by no means a hypothetical concern. The first wave of infrastructure attacks has already demonstrated the harm that can be done as governments face the reality that the hacking threat is increasingly about more than stolen information.
Late last year, in a first of its kind, a major cyberattack crippled Ukraine’s electricity grid, freezing the computer terminals of operators trying to restart the grid and blocking the telephone lines so consumers couldn’t call in. Last month, Israel’s Public Utility Authority was reportedly attacked. And Germany reported extensive damage to an industrial plant from a hacked blast furnace that couldn’t be stopped.
Closer to home, the Department of Homeland Security received reports of close to 250 infrastructure incursions in fiscal 2014, while Iranian hackers in December 2013 reportedly infiltrated the sluice gate controllers of the Bowman Avenue Dam in Rye, New York.
The potential losses in terms of time, money and possibly even lives from increasingly sophisticated attacks are hard to calculate. But one thing is clear: These attacks can only be stopped if we enlist the help of every Internet user.
And there is a good reason to follow this approach, because although cyberattacks weave their way through computer networks in different ways, there is a common thread that runs across many of them — something that we could exploit to stop them.

First, for efficiency reasons, many cyberattacks utilize the same attack pattern. From the attack on the Justice Department to the one crippling Ukraine, most utilize spear phishing.

The hacker hides a malware payload in the attachment of an email, which when clicked opens a back door into computer networks that are then used to hijack system controllers or extract data. Some phishing