Three Lessons From the San Francisco Muni Ransomware Attack

By Laurie Kumerow, Consultant, Code42

On Black Friday, a hacker hit San Francisco’s light rail agency with a ransomware attack. Fortunately, this story has a happy ending: the attack ended in failure. So why did it raise the hairs on the back of our collective neck? Because we fear that next time a critical infrastructure system is attacked, it could just as easily end in tragedy. But it doesn’t have to if organizations with Industrial Control Systems (ICS) heed three key lessons from San Francisco’s ordeal.

First, let’s look at what happened: On Friday, Nov. 25, a hacker infected the San Francisco Municipal Transportation Agency’s (SMFTA) network with ransomware that encrypted data on 900 office computers, spreading through the system’s Windows operating system. As a precautionary measure, the third party that operates SMFTA’s ticketing system shut down payment kiosks to prevent the malware from spreading. Rather than stop service, SMFTA opened the gates and offered free rides for much of the weekend. The attacker demanded a 100 Bitcoin ransom, or around $73,000, to unlock the affected files. SFMTA refused to pay since it has a backup system. By Monday, most of the agency’s computers and systems were back up and running.

Here are three key lessons other ICS organizations should learn from the event, so they’re prepared to derail similar ransomware attacks as deftly:

1. Recognize you are increasingly in cybercriminals’ cross hairs.

Cyberattacks on ICS systems, which control public and private infrastructure such as electrical grids, oil pipelines and water systems, are on the rise. In 2015, the U.S. Industrial Control Systems Cyber Emergency Response Team (ICS-CERT) responded to 20% more cyber incidents than in 2014. And for the first time since the agency started tracking reported incidents in 2009, the critical manufacturing sector experienced more incidents than the energy sector. Critical manufacturing organizations produce products like turbines, generators, primary metals, commercial ships and rail equipment that are essential to other critical infrastructure sectors.

2. Keep your IT and OT separate.

Thankfully, the San Fran Muni ransomware attack never went beyond SFMTA’s front-office systems. But, increasingly, cyber criminals are penetrating control systems through enterprise networks. An ICS-CERT report noted that while the 2015 penetration of OT systems via IT systems was low at 12 percent of reported incidents, it represented a 33 percent increase from 2014. Experts say the solution is to adopt the Purdue Model, a segmented network architecture with separate zones for enterprise, manufacturing and control systems.

3. Invest in off-site, real-time backup.

SFMTA was able to recover the encrypted data without paying the ransom because it had a good backup system. That wasn’t the case with the Lansing (Michigan) Board of Water & Light. When its corporate network suffered a ransomware attack in April, the municipal utility agency paid $25,000 in ransom to unlock its accounting system, email service and phone lines.

If San Francisco’s example isn’t enough to motivate ICS organizations to take cybersecurity seriously, then Booz Allen Hamilton’s 2016 Industrial CyberSecurity Threat Briefing should do the trick. It includes dozens of cyber threats to ICS organizations.