Dallas city officials have added extra encryption and other security measures to the outdoor warning sirens hacked early Saturday.
The hack also prompted the city to evaluate critical systems for potential vulnerabilities, City Manager T.C. Broadnax said in a statement late Monday. City officials are reviewing security for financial systems, a flood warning system, police-fire dispatch and the 911/311 system.
Broadnax told reporters separately on Monday that the hack came over a radio frequency and not over a wired computer network. The attack was “not a system software issue; it was a radio issue,” he told the Dallas Observer and others.
