How to stop cyberattacks crushing cities across the US

Cities and states across the U.S. are facing an increasing number of cyberattacks from individuals holding important government data hostage and demanding huge sums of money for its safe return.

The attacks, which involve a type of malware called ransomware, have become more frequent and destructive in recent years, with several high-profile attacks hitting cities from New Jersey to California. And the price tag to recover from these attacks can easily eclipse the million-dollar mark.

Just last month Lake City, Florida paid $460,000 in ransom to get its systems back, and Baltimore, Maryland is expected to pay $18 million to repair its infected infrastructure, despite not paying a ransom.

"The bad guys will always be one step ahead," explained University of Maryland, Baltimore County cybersecurity professor Richard Forno. "And we should never expect there to be total security. What we need to do is plan."

These attacks can force entire governments offline. Citizens can’t pay bills, developers can’t get work permits, and police have seen important investigations slowed.

Entire governments left offline

Ransomware is a form of malware that works its way into computer networks and locks down files and folders using data encryption. The most common way for an infection to take hold is via a simple email. Hackers use social engineering techniques to trick users into opening emails and clicking on links or downloading files that contain the malware. From there, the infection can spread across entire networks with ease, encrypting files and blocking access to them.

There's no way to unencrypt a locked file or database without the proper key. And, unfortunately, only the attacker holds it. That's where the ransom comes in. In exchange for anywhere from hundreds to thousands of dollars, usually paid in bitcoin, the attackers promise to provide the key that will unlock a victim's files.

There isn't one single form of ransomware. And locating the attackers is difficult, since they can mask their locations online. A number of ransomware variants exist in the wild, with an array of capabilities. Some even give cybercriminals a way to spy on networks to determine how large of a ransom they can demand.

One of the most dangerous versions is based on a National Security Administration tool used to hack into Windows PCs that was stolen by a hacker collective called The Shadow Brokers. That tool, called EternalBlue, has since spread across the world and has been employed in a number of attacks.

"The more sophisticated ransomware variants out there, we do see them doing reconnaissance on a network," explained FBI supervisory special agent Adam Lawson.