Cloud systems operated by IBM and AT&T for the US federal government were breached numerous times by foreign hackers, and the companies concealed the breaches from the government, according to a whistleblower’s lawsuit, Bloomberg reported.

William Barlow, IBM’s former vice president of threat intelligence, alleged in the complaint that the cloud systems in question were hit by breaches over the years by hackers linked to China and other foreign governments, and made false assurances about the safety of their systems in order to keep federal contracts, the report said.

The allegations involve a cloud system called Core Network used by the US military and other parts of the government, which is operated by AT&T on behalf of IBM.

Undisclosed hacks

Barlow said he personally witnessed numerous breaches of the network and was pressured by executives to downplay the incidents in internal reports and omit details.