The company flag flies in front of Boston Scientific Headquarters in Natick, Massachusetts.JB Reed | Bloomberg | Getty ImagesBoston Scientific said Wednesday it was hit with a cyberattack this week that is affecting its operations. The disclosure sent shares of the $72 billion medical device maker lower.The attack is disrupting Boston Scientific's access to company information systems and applications, including shipments services, the company said in a SEC filing."While the company is working diligently to restore affected functions and systems access, the timeline for a full restoration is not yet known," the filing said.Shares were down 5% in premarket trading on Wednesday. Shares of the maker of devices such as pacemakers and stents have been nearly cut in half already this year, under pressure after issuing a weak profit forecast in the first quarter.