WhatsApp's rollout of a new username feature carries significant cybersecurity risks, according to warnings from Finnish authorities.
The update allows users to display a chosen handle rather than their phone number, but experts caution that failure to register a username promptly could leave accounts vulnerable to impersonation scams.
The Finnish Transport and Communications Agency (Traficom) Cybersecurity Centre highlighted the potential for bad actors to exploit the transition period.
If legitimate users do not claim their desired usernames quickly, malicious actors could register them and use the handles to launch convincing phishing or social engineering attacks against the user's contacts.
The development mirrors a similar move by rival secure messaging app Signal, which introduced an identical service in 2024.
That platform's rollout was accompanied by similar warnings about the importance of early adoption to secure identity integrity on the network.