The Federal Bureau of Investigation has released a security notice that specifically warns emergency call centers against a new threat. FBI investigators have noticed that there is a high probability that telephony denial of service (TDoS) attacks are going to flood these centers with the intention of taking them offline. A TDoS attack is quite simple in its execution. Much like how a distributed denial-of-service (DDoS) attack floods a computer server with too many requests from multiple locations, a telephony denial-of-service attack floods a target that uses telephones in the same manner.
The security notice speaks of the threat as follows:
Public Safety Answering Points (PSAPs) are call centers responsible for connecting callers to emergency services, such as police, firefighting, or ambulance services. PSAPs represent key infrastructure that enables emergency responders to identify and respond to critical events affecting the public.
TDoS attacks pose a genuine threat to public safety, especially if used in conjunction with a physical attack, by preventing callers from being able to request service. The public can protect themselves if 911 is unavailable by identifying in advance non-emergency phone numbers and alternate ways to request emergency services in their area.
As for sources and motives of the potential TDoS attacks, the FBI does not single out specific sources. The notice states that hacktivists may use the TDoS to push their agenda, whereas cybercriminals may seek financial gain by holding the emergency call center hostage.
The FBI advises civilians to prepare for 911 outages by following these steps: See if text-to-911 is available in your area: save non-emergency contact numbers for fire, rescue, and law enforcement, sign up for automated emergency notifications from where you live (county, city, etc.) to be kept aware of incidents, and finally, find social media and other websites of emergency services in your area for potential point-of-contact.