Use this reputable service to check if your own credentials have been compromised in known breaches.
To safeguard yourself against the very breaches these combo lists represent, always:
While it may be tempting to search for a "517K COMBO LIST UPDATE zip" to bolster your cybersecurity testing or research, downloading such files from the open web is fraught with significant risks. These "combo lists"—collections of usernames and passwords typically harvested from various data breaches—are often hosted on untrustworthy platforms and can lead to severe consequences for both your personal security and your digital environment. The Dangers of Downloading Combo Lists