Investing.com - Global accounting firm Deloitte confirmed Monday that it was the victim of a cyber-attack.Deloitte said in a statement that attackers accessed data from the company's email platform.The statement confirmed a report by the Guardian newspaper, which broke news of the hack on Monday.The attack, which appeared to target the firm's U.S. operations, was discovered in March, and could have begun as early as October 2016, according to the Guardian.Deloitte is a ""Big Four"" firm that provides accounting, auditing and consulting services, including advice on mergers and acquisitions.It also runs a cyber security business.