WASHINGTON/LONDON/SAN FRANCISCO—Hackers working on behalf of China’s Ministry of State Security breached the networks of Hewlett Packard Enterprise Co and IBM, then used the access to hack into their clients’ computers, according to five sources familiar with the attacks.
The attacks were part of a Chinese campaign known as Cloudhopper, which the United States and Britain on Dec. 20 said infected technology service providers in order to steal secrets from their clients.