The bad actor had one goal in mind; money. Wreaking havoc on the county added up to about two to three thousand dollars for the adversary, and once they stopped making money, the calls stopped. “Thanks to our partnership with Cisco Talos and some of the intel it was able to find, it turned out that this actor was being paid by a third party to tie up the phone lines by having long conversations,” Cox said.
The hacker launched what’s called a telephony denial service attack (TDoS).
Here’s how it works. He or she buys up phone numbers through a third party and uses a server based in Europe and made it look like a local number. That makes it an international call, which carriers have to pay for, allowing the 3rdparty to profit. For its part, the hacker makes pennies for the minutes it ties up a phone line.