Dropbox’s move last week to ask users who had signed up before mid-2012 to change their account passwords followed the discovery of a large dump of email addresses and passwords related to these accounts.
The online storage company confirmed late Tuesday reports that 68 million user email addresses and hashed and salted passwords from an incident in 2012 had been compromised.
Dropbox said that the password reset the company completed last week covered all of the affected users so that the Dropbox accounts are protected.
Last week, the company asked users who signed up before mid-2012 to change their passwords if they haven’t done so since then, describing it as a preventive measure and not because there was any indication that their accounts were improperly accessed.
Hackers stole over 60 million account details from the online storage platform in the previously disclosed breach, Motherboard reported earlier on Tuesday. "Not just a little bit hacked……but proper hacked to the tune of 68 million records," wrote Troy Hunt, creator of the Have I been pwned? (HIBP) website set up for users to check if they have been hit by known data breaches.
The company did not comment on how the account information had been breached.
"There is no doubt whatsoever that the data breach contains legitimate Dropbox passwords, you simply can't fabricate this sort of thing," Hunt said. He added that there were now over 68.6 million Dropbox accounts that could be searched on the HIPB website, with some 144,136 email alerts sent to subscribers of its free notification service.
In July 2012, Dropbox said its investigation found that usernames and passwords recently stolen from other websites were used to sign in to a small number of Dropbox accounts. It said it had contacted the users affected to help them protect their accounts. A stolen password was also used to access an employee Dropbox account containing a project document with user email addresses, leading to spam attacks, the company said at the time.
"We've confirmed that the proactive password reset we completed last week covered all potentially impacted users," said Patrick Heim, Dropbox's head of trust and security, in an emailed statement on Tuesday. "We initiated this reset as a precautionary measure, so that the old passwords from prior to mid-2012 can’t be used to improperly access Dropbox accounts."
Heim encouraged users to reset passwords on other services if they suspect they may have reused their Dropbox password.