All but 16,000 of the credit and debit card numbers were encrypted, the officials said.

The state's Department of Revenue became aware of the breach Oct. 10 and an investigation revealed the hacker had stolen the data in mid-September, after probing the system for vulnerabilities in late August and early September.

The vulnerability exploited by the attacker was closed Oct. 20.

During a press conference Friday, South Carolina Governor Nikki Haley described the attack as international and "creative in nature."

Asked if she knew where the attack originated from, she said she does but declined to name the location because it might hurt the law enforcement investigation. She did, however, say she wants the hacker "slammed to the wall."