New York Attorney General Letitia James said Tuesday she will open a probe into the massive Capital One credit card breach.

About 100 million Americans had their personal information — including 140,000 Social Security numbers and 80,000 bank account numbers — illegally accessed by a hacker, Capital One Financial Corp. said Monday.

“Today, 100 million consumers across America are wondering if they were unfortunate enough to be a victim of the most recent data breach,” James said in a statement. “Though Capital One’s breach was internal, the fact still remains that safeguards were missing that allowed for the illegal access of consumers’ names, Social Security numbers, dates of birth, addresses, and other highly sensitive, personal information.”

“My office will begin an immediate investigation into Capital One’s breach, and will work to ensure that New Yorkers who were victims of this breach are provided relief,” the state AG said.

The hacker — 33-year-old Seattle resident Paige Thompson, a former software engineer at an Amazon subsidiary — was arrested after she tried to share the information online, authorities said.