Stems and methods for securing a service by detecting client-side web page tampering

A system, comprising:

• a processor;
• and
• a memory having programming instructions stored thereon, which, when executed by the processor, cause the processor to:
• monitor, with a MutationObserver instance, a web page Document associated with a Document Object Model (DOM) of a browsing session of a user;
• detect one or more event-based mutations of the web page Document;
• store the one or more event-based mutations in the memory;
• retrieve, from a profile repository, user behaviometric history data;
• compare the one or more event-based mutations to the user behaviometric history data;
• and
• deny continuation of the browsing session based on a predetermined similarity mismatch of the one or more event-based mutations to entries in the user behaviometric history data and output one or more indications of potential fraud.

A non-transitory computer-readable medium having stored thereon software instructions that, when executed by a processor, cause the processor to perform a method of:

• monitoring, with a MutationObserver instance, a web page Document associated with a Document Object Model (DOM) of a browsing session of a user;
• capturing one or more event-based mutations of the web page Document;
• retrieving, from a profile repository, user behaviometric history data;
• responsive to comparing the one or more event-based mutations to the user behaviometric history data, denying continuation of the browsing session based on a predetermined similarity mismatch of the one or more event-based mutations to entries in the user behaviometric history data and output one or more indications of potential fraud.