Abstract: A method implemented by a network device is disclosed to detect and mitigate account takeover attempts. The method includes generating a site profile for a site based on analyzing historical login requests to the site, wherein the site profile for the site includes information regarding legitimate login requests to the site and information regarding attacker login requests to the site, intercepting a login request to the site, determining whether the login request is legitimate for the site based on comparing the login request to the site profile for the site, assigning a risk score to the login request based at least in part on a result of the determination of whether the login request is legitimate for the site, determining a mitigation strategy to apply to the login request based on the risk score assigned to the login request, and causing the mitigation strategy to be applied to the login request.