Multiple sources are reporting that the business-oriented social network LinkedIn has experienced a significant security breach.
Reports indicate that as many as 6.4 million passwords have been compromised and posted by hackers on the Internet.
Though the passwords are in encrypted form, reports indicate that they are being cracked at a rapid rate, with somewhere near 300,000 passwords already revealed, putting those LinkedIn members' accounts at risk.
Security Week's Steve Ragan quotes @Securityninja as having tweeted a confirmation that the encrypted passwords can be cracked: "btw after getting the list of @linkedin hashes and hashing my old pwd with no salt there is a match for the hash in the list".
LinkedIn sent out a particularly brief statement on the breach, saying "Our team is currently looking into reports of stolen passwords. Stay tuned for more."
It is highly recommended that all LinkedIn users immediately change their passwords.
Source: http://www.securityweek.com/rumor-linkedin-hacked-password-hashes-dumped-russian-forum