How does pastejacking work in clipboard attacks?

Pastejacking is a technique where a malicious webpage hijacks the `copy` event via JavaScript, replacing the copied text with malicious content. For example, a user copies what appears to be a harmless command, but actually pastes a dangerous payload. This attack is detailed in [Penetration Techniques - Exploitation of Clipboard in Windows](/news/penetration-techniques-exploitation-of-clipboard-in-windows).