TeleMessage, the app that President Donald Trump’s former national security adviser, Mike Waltz, appeared to use to archive his group chats, has suspended all services after hackers claimed to have stolen files from it.

TeleMessage lets users archive their chats in secure messaging apps. However, the hacker reportedly found that TeleMessage’s archived chat logs aren’t end-to-end encrypted, allowing them to access the contents of certain messages, government official contact information, and login credentials for the service’s backend.

The communications app TeleMessage, which was spotted on former US national security adviser Mike Waltz's phone, has suspended “all services” as it investigates reports of at least one breach.