The Chicago, Illinois-based company is one of the largest commercial insurers in the United States, offering cyber insurance policies alongside a broad range of other insurance products.

In a March 23 announcement, the company revealed that, over the weekend, it fell victim to a cyberattack that impacted certain systems, and which resulted in network disruptions.

“On March 21, 2021, CNA determined that it sustained a sophisticated cybersecurity attack. The attack caused a network disruption and impacted certain CNA systems, including corporate email,” the company says in an incident notification on its website.