Michael Dell's return to the public markets after a protracted absence has helped make him $12 billion wealthier. The man who became famous selling computers more cheaply over a newish thing called the internet retreated from Wall Street's glare in 2013, delisting a company in which he held a stake of just $3.8 billion as sales of personal computers sagged.

Global computer maker Dell Technologies has admitted that hackers may have tried to break into its customers' accounts as it detected "unauthorised activity" on its network this month.The company has also hired a digital forensics firm to conduct an independent investigation and engaged law enforcement. No Dell products or services were affected, the company said on Wednesday.