DreamHost detect some unauthorized activity within one of their database. They notified their customers about the security breach and recommends them to change their FTP/shell access passwords, also email passwords.
"Our security systems detected the potential breach this morning and we immediately took the defensive precaution of expiring and resetting all FTP/shell access passwords for all DreamHost customers and their users." said in the official email notification.
Following the security breach, DreamHost start to change the customers' FTP/shell passwords for security purpose. Customers should login into their cpanel and change their passwords for FTP/shell.
According to their report, Only FTP password may have compromised but there is no unauthorized access to cpanel or email passwords.