Security notice for visitors to csebr.cz

Between approximately 21 July and 26 August 2026, the csebr.cz website was compromised. Logged-out visitors may have been shown a fake “I’m not a robot” verification prompt. After clicking it, they may have been instructed to run a command using Windows+R, PowerShell, or Terminal.

Simply seeing or clicking the fake “I’m not a robot” prompt did not, by itself, compromise your computer. The risk arose only if you followed the subsequent instructions and actually ran the copied command.

If you actually ran the command

  • disconnect the device from the internet;
  • do not use it for email, online banking, or work accounts;
  • using a different, trusted device, change important passwords, terminate active sessions, and enable multi-factor authentication;
  • contact the IT support team at your university, institute, or employer, and also email us at csebr@csebr.cz. If you do not have access to institutional IT support, contact us and we will help arrange the next steps.

ČSEBR will never ask you to run a command, install software, or enter a password.

The original compromised installation was taken offline, and the website was rebuilt separately from clean sources. We apologise for the incident.