Stryker's shares fell about 3% on Wednesday after the Wall Street Journal reported that the medical equipment maker was hit by a suspected Iran-linked cyberattack.
The company is experiencing a global outage across its systems. Staff and contractors have claimed that the logo of an Iran-linked hacking group has appeared on the login pages, the report said. Reuters could not immediately verify the report.
The outages began shortly after midnight on the East Coast, WSJ said, citing people familiar with the matter.
The company's staff found that remote devices running Microsoft's Windows operating system - such as cellphones, laptops and others configured to connect to Stryker's technology systems - had been wiped.
Stryker did not immediately respond to Reuters' request for comment.
Handala reportedly behind attack on Stryker
The logo of Handala, a pro-Palestinian hacking group, appeared on login pages, according to people familiar with the matter and social media posts, the report said.
The hacking group was also behind a breach of the Academy of the Hebrew Language's website on Wednesday. The hackers temporarily replaced the website with a message saying users would have no reason to keep learning Hebrew, as they "would not need it for much longer."