Prospect Medical Holdings, a chain that owns hospitals, as well as more than 165 outpatient facilities, said ransomware hackers had breached its system.

Hundreds of United Airlines flights were disrupted on Wednesday evening as the carrier grappled with a major computer system outage. The airline requested ground stops at its major hubs in the U.S.

A second cyber incident at data provider CDK Global, whose software is used at 15,000 auto dealers, continued to slow operations to a near-standstill Thursday at US and Canada dealerships, the ...

A ransomware breach of a little-known computer network has shut down a key technical tool that the U.S. Marshals use to hunt fugitives via their cellphones.

Federal officials are scrambling to assess the damage and address flaws in a sprawling, heavily used computer system long known to have vulnerabilities.