AUSTIN (KXAN) — Central Texas 911 systems were impacted Sunday by an intentional attack, according to the Capital Area Council of Governments (CAPCOG).
The attack, known as a Telephony Denial of Service, or TDoS, caused the 911 call volumes to exceed capacity to intentionally overload 911 systems. Call issues were seen across Central Texas from Austin to Burnet County to Luling.
CAPCOG provides critical infrastructure and ensures that 911 systems are operational for 31 Public Safety Answering Points in Central Texas, according to the local government coalition.
The issue was first noticed in Round Rock around 1 p.m., a spokesperson said. CAPCOG worked with AT&T’s Resolution Center to solve the issue. Numbers receiving robocalls were identified and disconnected.
The spokesperson said normal operations returned around 8 p.m. Sunday. CAPCOG said it will work with AT&T to prevent the attack from repeating.
These were the agencies impacted in the attack:
- Austin Fire Department
- Austin Police Department
- Austin/Travis County EMS
- Burnet County Sheriff’s Office
- Cedar Park Police Department
- Fayette County Sheriff’s Office
- Georgetown Police Department
- Hays County Sheriff’s Office
- Kyle Police Department
- Lakeway Police Department
- Leander Police Department
- Llano County Sheriff’s Office
- Lockhart Police Department
- Luling Police Department
- Marble Falls Police Department
- Pflugerville Police Department
- Round Rock Police Department
- Taylor Police Department
- Texas State Police Department
- Travis County Sheriff’s Office
- University of Texas Police Department
The City of Austin said some problems included callers and dispatchers having difficulty hearing each other, automatic location not populating and calls being answered by neighboring jurisdictions.
The Hays County Sheriff’s Office posted around noon Sunday that the county was experiencing issues with its 911 system.
What is a TDoS attack?
Telephony Denial of Service (TDoS) attacks are when a flood of malicious inbound calls targeting public safety response systems like 911, according to the U.S. Department of Homeland Security. The attackers use automation to create hundreds or thousands of simultaneous calls.
According to the Cybersecurity and Infrastructure Security Agency, a TDoS incident happened in Houston in 2017 when a preprogrammed landline phone in an elevator malfunctioned. The device ended up placing consecutive 911 calls over a 10-hour period, preventing agencies from getting real emergency calls.
“While ruled an accident, malicious actors may exploit unsecured devices to initiate TDoS events,” the website reads.