https://www.cnbc.com/2017/09/25/deloitte-cyberattack-may-have-revealed-blue-chip-client-information.html >A cyberattack at Deloitte, one of the "big four" accounting firms, went unnoticed for months and may have revealed confidential client emails and plans, according to a report Monday from the British newspaper the Guardian. >The firm believes hackers gained access through Deloitte's email server. The breach could have also revealed usernames, passwords, IP addresses and health information for primarily U.S.-based clients, the newspaper said.