An unanimous user in a Russian forum is making claims he has successfully hacked into Linkedin and leaked 6.5 million users passwords by uploading them.
This has caused security expert to warn users to change their passwords as soon as possible as a precaution.
The hackers posted the list of encrypted passwords to the forum to invite others to help in cracking the protected passwords.
Linkedin has yet been able to confirm the hack of any encrypted passwords, that are said to be protected by an encryption using an algorithm known as SHA-1, which is considered very secure, but other source are giving the claims creditability.
Security expert Per Thorsheim says that many users are reporting they are finding their passwords hashed to the list released by the alleged hackers.
Another security expert, Graham Cluley, working for Sophos, issued the warning of changing passwords to Linkedin users before any of their vital information might be compromised.
“Although the data which has been released so far does not include associated email addresses, it is reasonable to assume that such information may be in the hands of the criminals,” Cluley added.
Linkedin themselves was said to be looking into the seriousness of the hacking claims. LinkedIn, a professional social networking site, reports more than 150 million registered users in more than 200 countries and territories.