NEW YORK, July 19 -- The shares of cybersecurity giant CrowdStrike tanked on Friday as a defect in its service caused worldwide IT outage.

CrowdStrike shares opened at 294.51 U.S. dollars per share, down 16.48 percent from previous close, and its shares lost more than 8 percent in the morning session.

"CrowdStrike is actively working with customers impacted by a defect found in a single content update for Windows hosts," said the Austin-based company in a statement Friday morning.

CrowdStrike said this disruption wasn't the result from a security incident or cyberattack and the issue has been identified and isolated with a fix deployed.

Some systems can be fixed and back up and running immediately -- but for others it "could be hours, could be a bit longer" before everything is back up and running, CrowdStrike CEO George Kurtz said in an interview with CNBC.

Meanwhile, trading service provider Charles Schwab warned that "certain online functionality may be intermittently slow or unavailable."

"Please do not place trades twice, as duplicate trades may be created," Schwab said in a message.

  - Xinhua