The leaks shown here do not mean that your infrastructure was breached. In almost all cases they come from endpoints infected by info stealer malware on the user side (customers, employees or partners).
The malware runs on the user device, extracts saved credentials, cookies and session tokens from the browser, and the resulting dumps are later published by third parties in public underground channels.
Attackers then reuse these credentials to access your portals, VPN or admin tools, sometimes bypassing multi factor authentication with stolen cookies. So even if the initial compromise happened outside your perimeter, the impact for your organisation can be real in terms of security and reputation.