Data breaches

The hack that occurred in December affected 27,746 mortgage customers, the South Carolina-based lender said.

After gaining access to On Q systems via vendor software, unknown parties were able to obtain and remove client personal information, including Social Security numbers.

Keeping vendor arrangements under wraps, "pen-tests" and a few simple email setting changes can make a world of difference in avoiding future attacks, experts say.

Malicious actors could be utilizing the same software that cybersecurity experts use to test a company's systems for vulnerabilities.

An unnamed hacker in December "potentially removed" sensitive consumer data including Social Security numbers from the wholesale lender.

The attack is one of three major incidents the lender has suffered in the past three years.

The root cause of the hack affecting over 5 million customers was an employee clicking on a link in a work-related search result, according to public case documents.

The New York-based firm said a hack last August compromised the personal identifiable information of 10,835 customers.

The ransomware attack compromised the personally identifiable information of over 199,000 mortgage customers.

The lender didn't reveal whether the incident was related to a purported ransomware gang attack last March.