The hackers say the attacks were launched to protest the TTIP and TPP, and to retaliate for the shooting of James Daniel McIntyre by Candian police.
The hackers are threatening to release all of the stolen data if the site isn't shut down.
The data potentially stolen includes names, birthdates, Social Security numbers and medical information.
According to the New York Times, Cardinals officials allegedly tried a series of passwords until they successfully accessed the Astros' network.
Recently unsealed documents indicate that a Chicago residence was searched in connection with the breach in October 2014.
Europol recently announced 49 arrests in connection with the fraud campaign.