The Anatomy Of The Twitter Attack

At Hotmail, Hacker Croll again attempted the password recovery procedure - making an educated guess of what the username would be based on what he already knew. This is the point where the chain of trust broke down, as the attacker discovered that the account specified as a secondary for Gmail, and hosted at Hotmail was no longer active. This is due to a policy at Hotmail where old and dormant accounts are removed and recycled. He registered the account, re-requested the password recovery feature at Gmail and within a few moments had access to the personal Gmail account of a Twitter employee. The first domino had fallen.