Capital One said a hacker gained access to more than 100 million Capital One customer accounts and credit card applications earlier this year.

The compromised data includes 140,000 Social Security numbers, 1 million Canadian Social Insurance numbers and 80,000 bank account numbers, in addition to an undisclosed number of people’s names, addresses, credit scores, credit limits, balances, and other information, according to the bank and the US Department of Justice.

Paige Thompson, 33, was arrested in connection with the breach, the Justice Department said Monday. The department alleges that Thompson “posted on the information sharing site GitHub about her theft of information from the servers storing Capital One data.”

Thompson, who the DOJ indicated had worked previously as a tech company software engineer, was able to gain access by exploiting a misconfigured web application firewall, the DOJ said.

Capital One indicated it fixed the vulnerability and said it is “unlikely that the information was used for fraud or disseminated by this individual.” However, the company is still investigating.

The breach affected around 100 million people in the United States and about 6 million people in Canada, according to Capital One.

However, “no credit card account numbers or log-in credentials were compromised and over 99% of Social Security numbers were not compromised,” the company said.

Capital One said it will notify people affected by the breach and will make free credit monitoring and identity protection available.

It is not immediately clear if Thompson has an attorney representing her.