1. A system comprising: a computer-readable memory having computer-readable program code embodied therewith; a processor coupled to the computer-readable memory, wherein responsive to executing the computer-readable program code, the processor is configured to perform executable operations comprising: communicating at least one client request comprising a payload having a unique identifier to a Web-based application; receiving from the Web-based application response HTML and an associated Document Object Model (DOM) object; identifying in the received DOM object the unique identifier communicated to the web-based application in the payload; and responsive to identifying in the received DOM object the unique identifier communicated to the web-based application in the payload, identifying as un-trusted a section of the received DOM object comprising content corresponding to the payload, which is identified in the received DOM object via the unique identifier.