The hack in which scores of passwords were stolen from Linkedin and eHarmony may have been done last year.
Users on the forum insidepro – to which the encrypted stolen passwords were posted – told SC Magazine they found their old LinkedIn passwords in the encrypted cache that were obsolete for between six and nine months.
Those users had regularly updated their passwords, placing the hack in about a three month period from around January based on their claims.
Others claimed through inside knowledge that the hack was made around the start of the year through SQL injection on the LinkedIn web site.
But LinkedIn refused to verify or refute the claims.
“Due to the ongoing investigation, we aren't disclosing the specific details and data related to what we found,” communications manager Deepa Sapatnekar said in a statement.
“The point is we were quickly able to confirm that these were in fact stolen LinkedIn passwords.”
The orginal uploader of the affected password cache, dwdm, did not respond to requests for comment.
Compromised passwords that appeared in the swiped cache were not tied to LinkedIn accounts and so each combination may have been used by multiple users.
LinkedIn was indeed quick to comment when news of the hack broke last week and it has now reset all affected passwords.
About 5.8 million passwords from LinkedIn and eHarmony were posted to insidepro on 3 June. The credentials were stolen before Linkedin had a chance to implement stronger security measures, including salting.
The passwords were encrypted with the SHA-1 hash function and were unsalted and therefore easier to crack with rainbow tables.
Sapatnekar said updates would be released via LinkedIn’s Twitter account and blog.
Were your LinkedIn or eHarmony passwords stolen? Were they new or outdated? Let us know in the comments below.