The company’s shares were down 2 percent at $159.26.
The social media giant had said hackers stole digital login codes that could have allowed them to take over nearly 50 million user accounts.
The company, however, said it was yet to determine whether the attackers misused any accounts or stole private information.
Workplace spokesperson said on Oct. 2 it currently did not have any evidence to suggest that any of its customers have been impacted.
“We are investigating and reaching out to customers directly to keep them informed,” the spokesperson said.
Business Insider first reported a potential issue with the app.