System and method for modifying web content via a content transform proxy service

A method of modifying at least one of an HTTP request and an HTTP response during a web transaction having a client side and a server side, comprising the steps of:

• making an HTTP request on the client side using a client Web browser, the HTTP request having a server-side destination;
• processing the HTTP request on the server side using outgoing proxy rules to determine whether to modify the HTTP request;
• passing on the processed HTTP transaction to the server-side destination;
• returning results of the processed HTTP request from the server-side destination;
• processing the HTTP response on the server side using incoming proxy rules to determine whether to modify the HTTP response;
• returning the processed HTTP response to the client web browser on the client side;
• setting up a sequence of filtering streams;
• reading one of the filtering streams;
• building a window of operation containing possible text of interest when one of the streams is read, wherein at least one regular expression is used to define a corresponding at least one rule that in turn defines the text of interest and actions required on the text of interest;
• creating a buffer by comparing the possible text of interest with text bounding the possible text of interest;
• determining whether the buffer matches a predefined condition;
• and
• when the buffer matches the predefined condition, handing off the buffer to another entity responsible for running the at least one regular expression.