State-backed hackers from China are believed to be behind a major breach at U.S.-based cybersecurity company F5, Bloomberg News reported on Wednesday, citing people familiar with the matter.
The breach, which went undetected for at least 12 months, targeted F5’s internal systems, according to the report. The company confirmed that a threat actor had gained unauthorized access but said the incident had no operational impact.
The U.S. Cybersecurity and Infrastructure Security Agency (CISA) earlier warned that federal networks were being targeted by an unidentified “nation-state cyber threat actor” exploiting vulnerabilities in F5 products.
Neither F5, CISA, nor the Chinese embassy in Washington immediately responded to Reuters’ requests for comment.
Bloomberg reported that F5 CEO François Locoh-Donou is personally briefing customers on the breach timeline and the involvement of China-linked hackers.
F5, listed on Nasdaq under the ticker FFIV.O, provides software and hardware solutions that secure applications and networks — making the breach particularly sensitive given the company’s role in protecting critical infrastructure and corporate systems.
The intrusion underscores growing U.S. concerns about state-sponsored cyber espionage, particularly from China, which Washington has repeatedly accused of conducting long-term infiltration campaigns against American government and corporate targets.
