A messaging service used by former National Security Advisor Mike Waltz has temporarily shut down while the company investigates an apparent hack. The messaging app is used to access and archive Signal messages but is not made by Signal itself.

404 Media reported yesterday that a hacker stole data "from TeleMessage, an obscure Israeli company that sells modified versions of Signal and other messaging apps to the US government to archive messages." 404 Media interviewed the hacker and reported that the data stolen "contains the contents of some direct messages and group chats sent using [TeleMessage's] Signal clone, as well as modified versions of WhatsApp, Telegram, and WeChat."

TeleMessage is based in Israel and was acquired in February 2024 by Smarsh, a company headquartered in Portland, Oregon. Smarsh provided a statement to Ars today saying it has temporarily shut down all TeleMessage services.

"TeleMessage is investigating a recent security incident," the statement said. "Upon detection, we acted quickly to contain it and engaged an external cybersecurity firm to support our investigation. Out of an abundance of caution, all TeleMessage services have been temporarily suspended. All other Smarsh products and services remain fully operational."

Last week, Waltz was photographed using the TeleMessage Signal app on his phone during a White House cabinet meeting. Waltz's ability to secure sensitive government communications has been in question since he inadvertently invited The Atlantic Editor-in-Chief Jeffrey Goldberg to a Signal chat in which top Trump administration officials discussed a plan for bombing Houthi targets in Yemen.

Waltz was removed from his post late last week, with Trump nominating him to serve as ambassador to the United Nations.