A hacker broke into Ventura County's computer system and emailed bogus county receipts to about 35,000 residents who used credit cards to pay their property taxes or court fees over the last several years, officials said Tuesday.
No credit card numbers or personal data were stolen, said Steven Hintz, the county's treasurer-tax collector. However, he said, he anticipates the hacker will ask for such details in future emails designed to look like official county correspondence.
"I haven't received any reports of a second set of emails, but I expect them," Hintz said, warning people not to respond to emails asking about online payments they made to the county.
The unknown hacker is based in the Philippines, according to county officials.
Ventura County residents started receiving the emails last weekend. They looked like receipts for payments dating back to 2007.
On Saturday night, computer experts found and fixed the flaw that made the system vulnerable, Hintz said. But the emails kept coming and by the end of Monday, Hintz, who received one himself, had fielded more than 1,000 inquiries from residents worried that someone would run up bills on their credit cards.
Officials said that would be impossible. They said such information is stored by a third-party vendor, not by the county's online payment system, which was the target of the hacking attack.
The leak in the county's computer system surfaced just weeks before the April 11 deadline for property tax payments.
"People should continue to pay their taxes any way they choose to," Hintz said. But he predicted that fewer than usual would choose to pay online this time.