https://www.theregister.co.uk/2017/09/25/deloitte_email_breach/

Deloitte, one of the world's "big four" accountancy firms, has fallen victim to a cyberattack that compromised sensitive emails.

The breach dates back to November 2016 but was only discovered in March, according to The Guardian, which broke the news through an exclusive on Monday. Deloitte has reportedly informed six of its clients that their information was "impacted". The firm's internal review into the incident is ongoing.