U.S. banks and other financial institutions have suffered their largest ever data breach.

U.S. officials confirmed the hack on Tuesday while bringing charges against four men for the theft of customer data of more than 100 million people. J.P. Morgan is among the banks that were hit, the company confirmed to Bloomberg.

Hackers gained access to customer information of nine companies, according to an indictment from Preet Bharara, U.S. Attorney in Manhattan, including two newspapers. The Wall Street Journal, which announced in October that it had been hacked, is among that group.

Preet Bharara held a press conference in which he touted the bust as "securities fraud on cyber-steroids," in which hackers gained access to a variety of systems that helped them generate money from numerous illegal activities including running a digital currency exchange and gambling websites. The group also participated in stock manipulation.

Bharara said that the group was also able to hack into the email accounts of a security firm that had been tracking their activities. That information was then used to avoid the firm's investigation.

Gery Shalon, Joshua Aaron and Ziv Orenstein face a variety of charges as part of the case.

U.S. authorities allege that the various schemes generated "hundreds of millions of dollars in illicit proceeds" that was than laundered through at least 75 shell companies and bank accounts around the world.

The WSJ had previously alerted its customers to the breach.