U.S. authorities announced Tuesday that they were indicting nine individuals over their alleged roles in an insider trading scheme that generated more than $100 million in illegal profits.

Federal cases were filed in New Jersey and Brooklyn. A parallel lawsuit was filed by the SEC. The authorities allege that over a five year period, traders worked in conjunction with overseas hackers to break into the servers of PRNewswire, Marketwired and Business Wire as a way to gain access to press releases and earnings data before they became public.

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Doing this, the government alleges, the traders were able to make trades based on this information and profit accordingly. The unsealed indictments (embedded below) also allege that the traders shared their profits with the hackers.

The stocks of the companies targeted include Panera Bread, Hewlett-Packard, Oracle and Bank of America.

SEC chairman Mary Jo White called the case "unprecedented in terms of the scope of the hacking at issue, the number of traders involved, the number of securities unlawfully traded and the amount of the profits generated."

Hacking the press release systems

Although insider trading cases aren't new, the way traders worked with hackers to target press websites for information before it goes public, certainly is a novel approach to access.

In a press conference held by the various agencies, authorities said that hackers often used traditional phishing exploit as a way to gain access to press releases and earnings documents.

Traders gave hackers a list of documents and companies to target. Once information was obtained — it could be just hours before the information became public — traders would make trades and profit accordingly.

In an emailed statement to Bloomberg, Business Wire said that it is cooperating with the Justice Department and has hired security professionals to "conduct additional forensic testing of its systems, and to provide assurance that Business Wire's network is fully operational and secure."

During the press conference announcing the indictments, authorities shifted discussion about the security practices at the press release companies and by their employees to the greater crime at stake.

"I would say this is a stark reminder to companies that your computers systems are vulnerable," said New Jersey U.S. Attorney Paul Fishman. Fishman also urged employers and employees to "be vigilant" as to their data.

A moving target

The real challenge for authorities was tracking down trades and tying it to hacks. During the press conference, authorities said investigators "sorted through literally millions of trades."

The press conference also revealed that videos were used to recruit traders and to show them how to access insider information.

Fishman called the hackers "relentless and patient," noting that they were willing to wait for the right time to target companies to again access various system.

The investigation that kicked off Tuesday's indictments started more than two years ago, after the FBI was tipped off by the SEC about some suspicious trades by some of the defendants.

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Dnj Indictment

Brooklyn Indictment

—Jason Abbruzzese contributed reporting to this story