Most modern communication applications—including Slack, Microsoft Teams, Apple iMessage, and various email clients—rely on automated regex algorithms to scan plain text and convert domain names into clickable hyperlinks.

The @ symbol in standard URL structures is technically used to pass user credentials to a site before the hostname (e.g., username:password@domain.com ).

Threat actors use this standard to build URLs that appear entirely legitimate to the human eye but redirect to .zip domains.

If a developer instructs a coworker to "download backup.zip ," the chat client may automatically hyperactive the word as a URL.