A hacker managed to hack TeleMessage — a modified government version of the Signal messenger — and gained access to the metadata and correspondence of at least 60 US officials, including employees of the White House, the Secret Service and the diplomatic corps.

In May 2025, a vulnerability in the TeleMessage application, used by US federal agencies, led to a large-scale data leak. The hacker gained access to messages and contacts, including those responsible for emergencies, foreign policy and the protection of senior officials. According to a Reuters investigation, the hacked data indicates interference in internal government communications, even if the content of some messages appears fragmentary.

The TeleMessage application, which adapts familiar messengers to government archiving requirements, has been used by Trump adviser Mike Walz, among others. It was his photo with the app at a government meeting that drew attention to the tool. The leak was made possible through a data archive that ended up at the disposal of Distributed Denial of Secrets, a non-profit organization that publishes leaked information in the public interest.

Despite assurances from individual agencies about the “absence of evidence of compromise,” experts point to the serious risk associated with access to metadata. Information about who communicated with whom and when could become invaluable for counterintelligence. The incident sparked a new wave of criticism of the cybersecurity of US government structures, as well as the advisability of using private digital solutions in the public sector.