By March 2013, Correa had guessed the employee's new password and used his login to spy on the information in Ground Control.
According to his plea deal, Correa accessed information such as how the Astros ranked every player eligible for that year's draft, along with other confidential data.
He broke in again at the end of July 2013 - during the crucial period before a key deadline for trading players - and reviewed notes about the Astros' trade negotiations.
Correa persisted even after the Astros updated their system. He logged in to the former employee's email account and found a default password the team had emailed to people with access to Ground Control to use until the next time they could sign in and change their passwords.
The FBI began investigating a potential breach in Ground Control after trade negotiation information that was stored in the database was leaked online in 2014, eventually uncovering Correa's scheme.
Altogether, the plea deal estimates that Correa's intrusions amounted to $1.7 million worth of damage to the team. So now he is headed to prison and will pay $279,038 in restitution. But the Astros also learned an expensive lesson about good password hygiene: Tweaking a password isn't enough to keep important accounts safe.