Masimo hit by massive cyberattack as it sells audio brands Denon, Polk to Samsung

Masimo Corporation, a global medtech company specialising in noninvasive monitoring technologies, disclosed a cyberattack that severely disrupted its activities. At the same time, Masimo said it is selling its audio products business, including world-class audio brands Bowers & Wilkins, Denon, Marantz, Polk, and others.

Masimo disclosed a cybersecurity incident in a filing with the Securities and Exchange Commission (SEC) alongside its quarterly earnings report and announcement of the sale of its consumer audio business, “Sound United,” for an aggregate purchase price of $350,000,000.

The company said it identified unauthorized activity on the on-premise network on April 27th, 2025.

The cyberattack impacted “certain” manufacturing facilities, which have been operating “at less than normal levels” since then. The company’s ability to process, fulfill, and ship customer orders in a timely manner has also been temporarily impacted.

Strata-gee reports that the Masimo.com website has been down for a few days, and the company did not respond to attempts to contact it.

“Upon detection, we activated our incident response protocols and implemented containment measures, including proactively isolating impacted systems,” the filing with the SEC reads.

“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 incident investigation remains ongoing, and the full scope and impact are not yet known. It’s unclear who is responsible for the attack. No ransomware gang tracked by the Cybernews Ransomlooker tool has claimed responsibility for the attack.

Masimo said it is working to assess the damage, mitigate, and remediate the incident with the assistance of third-party cybersecurity professionals and is coordinating the efforts with law enforcement.

At this time, Masimo believes that the incident “appears unrelated to and is not affecting the Company’s cloud-based systems.”

It’s unclear if any users of the products are affected by the cybersecurity incident. Cybernews reached out to Masimo for additional details and will include their response.

Masimo CEO Katie Szyman only briefly informed investors about the incident during the earnings call on Tuesday. Szyman mentioned that it impacted their websites and several other systems last week.

“The investigation is ongoing, but as of right now, we do not expect that this will have an impact on our guidance. Given the nature of these things, we appreciate your understanding that we will not be commenting more on this event during our earnings call today.”

Masimo Corporation is a global medical technology company that produces pulse oximetry, brain function monitoring, and wearable patient sensor products for hospitals and home care. Its market capitalization is almost $9 billion.

On May 6th, the company announced it is selling its audio business to Harman International, a subsidiary of Samsung Electronics. For $350 million, Samsung will acquire all the subsidiaries and a legendary portfolio of audio brands, such as Bowers & Wilkins, Denon, Marantz, Definitive Technology, Polk Audio, Classé Audio, Boston Acoustics, and others.