At nearly quarter to midnight on Friday, all 156 of Dallas’ emergency alarm systems went off. They’re designed to warn denizens of the Texas city about severe storms, tornados and other dangerous weather. But there was no sign of any natural cataclysm coming on the weekend. It soon emerged that hackers had set off all 156 of the outdoor warning sirens.
The Dallas Office of Emergency Management swiftly set to work turning all the alarms off before determining how to prevent further attacks. The OEM said it believed the system was hacked by someone within Dallas, but couldn’t say how the attack occurred. It had contacted the Federal Communications Commission, asking for assistance in determining who the perpetrator was.
As for the actual impact of the attack, not only did it cause significant noise throughout the city, as tweeted by some residents, it also caused a surge in 911 calls. That meant some who weren’t calling about the sirens couldn’t get through to emergency services.
The city is now looking at the cybersecurity of its public services. “This is yet another serious example of the need for us to upgrade and better safeguard our city’s technology infrastructure,” said Mayor Mike Rawlinson. “It’s a costly proposition, which is why every dollar of taxpayer money must be spent with critical needs such as this in mind. Making the necessary improvements is imperative for the safety of our citizens.”
Dallas OEM lead Rocky Vaz said neither its control nor remote login systems had been compromised. “We have now pinpointed it to one area where we think where they were able to get into our system and activate all the sirens, and put that into a mode where they send a signal so it’s active over 60 times.
The siren system is back online as of yesterday, according to a Dallas City Hall spokesperson. The investigation into what happened, who was responsible and what vulnerabilities they exploited continues.
It’s certainly not the first time a U.S. city’s public services have been hacked. In 2016, ransomware struck San Francisco’s light rail system, the Muni, while Dallas saw some of its traffic signs hacked that same year.