Medical device maker Masimo warns of cyberattack, manufacturing delays

Medical device company Masimo Corporation warns that a cyberattack is impacting production operations and causing delays in fulfilling customers’ orders.

Masimo Corporation is a California-based medical technology and consumer electronics maker. It’s best known for its noninvasive patient monitoring products like pulse oximeters, brain function monitors, hemodynamic monitoring systems, capnography and gas monitoring solutions, and remote patient monitoring platforms.

The company has a reported annual revenue of $2.1 billion (2024) and approximately 3,600 employees worldwide, while it is publicly traded on the NASDAQ (MASI).

The firm disclosed the attack in a Form 8-K filing submitted to the U.S. Securities and Exchange Commission (SEC) last night, stating the incident occurred on April 27, 2025.

While the company did not share details about the type of attack, they stated that the threat actors breached their on-premise network, causing the company to isolate impacted systems.

The disclosed cybersecurity incident has significantly impacted the company’s manufacturing and business operations.

“As a result of the incident, certain of the Company’s manufacturing facilities have been operating at less than normal levels, and the Company’s ability to process, fulfill, and ship customer orders timely has been temporarily impacted,” reads the 8-K filing.

“The Company has been working diligently to bring the affected portions of its network back online, restore normal business operations and mitigate the impact of the incident.”

The firm believes that the network breach was isolated to on-premise systems, not affecting its cloud-based infrastructure.

Masimo clarified that the investigation into the exact nature, scope, and actual impact of the incident is still underway, so it’s unclear if it has affected customer data and whether it will have any impact on the company’s financial figures for the running quarter.

Masimo says they are working with external cybersecurity experts and have notified law enforcement.

At the time of writing, no ransomware groups have assumed responsibility for the attack at Masimo.