Patent attributes
A computerized method and system for detecting access of a protected server by malicious bots are provided. The method comprises receiving a request from a client machine; generating a polymorphic script code challenge that includes a scrambled secret; sending the polymorphic script code challenge to the client machine in response to the received request; receiving a token from the client machine in response to the polymorphic script code challenge; comparing contents of the token to the secret in its unscrambled form; and determining the client machine to be a malicious bot in an event including any one of the token does not match the secret and a token has not been received, wherein a new polymorphic script code challenge containing a new scrambled secret is generated for each new request received from a client machine.