Abstract: Systems and/or techniques for facilitating automatic detection of proxy-based phishing sites are provided. In various embodiments, a system can access a computer-executable web resource and can embed an authorization verification logic within the computer-executable web resource. In various aspects, upon execution of the computer-executable web resource, the authorization verification logic can be configured to: identify a computing domain via which the computer-executable web resource is being executed; compare the identified computing domain with one or more authorized computing domains; determine that the identified computing domain is an unauthorized proxy site if the identified computing domain does not match at least one of the one or more authorized computing domains; and initiate a remedial action based on determining that the identified computing domain is an unauthorized proxy site.