I believe KVSTool sends the following
Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)
Rather than the conventional web browser standard shown on that page linked above, which would be something like
Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.1) KVSTool/7.7.0
If this is indeed the case (and please feel free to provide the actual string you use), surely the tool is
fraudulently (
done to trick someone for the purpose of getting something valuable) pretending to be a different web browser? It seems the company that provides the KVSTool web browser claims it's a special custom web browser, and it isn't MSIE 6.
If KVSTool isn't trying to hide itself from the servers your clients are using, why wouldn't it identify itself using the standard HTTP UserAgent string?