The leaked information, comprising 58,978 username and password combinations, appeared Monday on Pastebin. While Twitter said that it's investigating the breach, it’s also downplayed the supposed size and severity of the data dump.
"We are currently looking into the situation," said spokeswoman Rachel Bremer via email. "It's worth noting that, so far, we've discovered that the list of alleged accounts and passwords found on Pastebin consists of more than 20,000 duplicates, many spam accounts that have already been suspended, and many login credentials that do not appear to be linked (that is, the password and username are not actually associated with each other)."
Most hackers dumping data on Pastebin only divulge a subset of their data, then link to a torrent file for anyone who wants to download the entire data set. But in this case, whoever posted the data simply pasted the information across five different Pastebin posts. (Links: one, two, three, four, and five.) That was necessary since Pastebin imposes a 512 Kb limit on each post.
[ Are you ignoring common social media privacy controls and sharing risks? See Facebook Privacy: 5 Most Ignored Mistakes. ]
While Twitter is continuing its investigation, the company said it's already contacted affected users. "We have pushed out password resets to accounts that may have been affected," said Bremer. "For those who are concerned that their account may have been compromised, we suggest resetting your passwords and more in our Help Center."
Still, few Twitter users would have been affected by the breach. Based on Twitter's estimate of the number of invalid accounts contained in the data dump, and with the social network claiming to now have over 140 million active users, the breach would have affected about 0.02% of its user base.
Who leaked the Twitter account credentials, and why? Thanks to the Pastebin poster remaining anonymous, and no group stepping forward to take credit, that's not clear. But it's quite possible that the leaked credentials were gathered via phishing attacks, which would have tricked users into divulging their details. If so, that would exonerate Twitter and its information security practices.
That question is relevant because last year, as part of its settlement with the Federal Trade Commission settlement, Twitter agreed to improve its information security practices, undergo regular information security audits for 10 years, and avoid making any misleading statements about the effectiveness of its security or privacy practices for the next 20 years.
The settlement stems from an FTC charge that the social network "deceived consumers and put their privacy at risk by failing to safeguard their personal information," after hackers in 2009 twice gained full administrative control of the Twitter site.
As part of the settlement, which was first fielded by the FTC in 2010, Twitter agreed to designate employees to coordinate--as well as be accountable for--its information security and privacy programs. Twitter also agreed to put in place "reasonable safeguards" to mitigate any information security risks it identified, and to store data securely. But by the time the settlement was announced last year, Twitter said it had added almost all of the required security improvements.
Put an end to insider theft and accidental data disclosure with network and host controls--and don't forget to keep employees on their toes. Also in the new, all-digital Stop Data Leaks issue of Dark Reading: Why security must be everyone's concern, and lessons learned from the Global Payments breach. (Free registration required.)