Australian shipbuilder Austal Limited’s data management system was hit with a data breach that exposed staff contact information, but the company does not believe any sensitive defense data was involved.

The malicious actor, on an unnamed date, managed to access some employee email and phone numbers and then tried to sell the illegally collected information on the internet, as well as, extort money from the company, Austal said in a statement. Per company policy, no response was given to the blackmail attempt.

“No company wants to lose control of its information, but there is no evidence to date to suggest that information affecting national security nor the commercial operations of the company have been stolen: ship design drawings, which may be distributed to customers and fabrication sub-contractors or suppliers are neither sensitive nor classified,” the company said.

Company IT workers have patched the breach and added additional security measures to prevent similar incidents from occurring in the future.