Michigan-based Flagstar Bank, which has more than 150 branches across several US states, has disclosed a data breach that involved threat actors accessing files containing the personal information of 1.5 million individuals.
According to a data breach notification posted on Flagstar’s website and information provided by the company to authorities, the breach occurred in early December 2021. An investigation finalized on June 2 showed that the attackers had accessed files storing personal information.
It seems that different types of data were compromised for different customers, but the attacker appears to have obtained the social security numbers of at least some people. Affected individuals are being notified through snail mail.
The company said it does not have evidence that the compromised information has been misused, but it has decided to provide affected individuals two years of free identity monitoring services.
It’s unclear if the attack involved ransomware or any other type of malware. SecurityWeek has reached out to Flagstar for clarifications and will update this article if the company responds.
This is not the first time Flagstar has been targeted by cybercriminals. In March 2021, the bank started informing customers that it was one of the many companies affected by a hack involving a file transfer service from Accellion.
The Accellion service was compromised in late 2020, allowing cybercriminals to access the files of tens of organizations that had been using the service. In March 2021, the Cl0p ransomware gang published data stolen from Flagstar on its leak website.
The Accellion incident also impacted nearly 1.5 million Flagstar customers and the financial institution ended up reaching a $5.9 million deal to end litigation.
Related: Morgan Stanley Hit by Accellion Hack Through Third-Party Vendor
Related: Accellion Reaches $8.1 Million Settlement Over FTA Data Breach