Adult FriendFinder found that nearly 4 million of its users' accounts have been compromised by hackers who have already begun spamming the email accounts of victims.

The next phase of the cyberattck could see the stolen information used to blackmail high-profile users of the adult network.

The cyber attack exposed the usernames, dates of birth, email addresses, computer IP addresses, zip codes, marital statuses and sexual preferences of 3.9 million Adult FriendFinder accounts.

Adult FriendFinder, a social network for adults seeking casual sex, has over 60 million user accounts and is part of the larger FriendFinder Network, which has more than 600 million members.

The FriendFinder Network just confirmed the massive data breach and said it only recently learned of the intrusion. The organization is launching an internal investigation to review its existing security protocols and expand them where necessary.

Right now, the company says there's no evidence that passwords of financial details were compromised as a result of the security breach, but it can't rule out the possibility that the breach is more widespread than it appears right now.

"As is common with similar cyber-attack events, until the investigation is completed, it will be difficult to confirm the full scope of the incident, but we will continue to work vigilantly to address this potential issue and will provide updates on this site as we learn more from our investigation," stated the FriendFinder Network.

The FriendFinder Network is temporarily disabling its search function for usernames. It's also masking the usernames of accounts it believes were compromised as a result of the cyber attack.

As soon as the organization learned of the data breach, it contacted the Federal Bureau of Investigation and other law enforcement agencies, it says.

The security breach may have been spotted first by Channel4 News in the UK, which had been doing a bit of investigative journalism and taking a look into the Internet's underworld. That investigation led the media outlet to a clandestine forum, where a hacker nicknamed "ROR[RG]" shared information stolen from Adult FriendFinder accounts.

Shortly after the information was leaked deep inside of the "darkweb," other hackers on that forum began feeding the information into their spam bots.

The types of information leaked after the data breach could be enough to successfully build profiles of the victims, search out the most prominent individuals among them then start a blackmail campaign against them.