no404 and PNG (image) returning from web site

[Noam Rathaus]

Hi,

I came across a false positive generating server, the server will return a
picture (that changes) for whatever request you give it. It seems that no404
is not able to handle this. Here is an example:
GET /cgi-bin/nessus_is_probing_you_722269810 HTTP/1.1.
Connection: Close.
Host: host:8080.
Pragma: no-cache.
User-Agent: Mozilla/4.75 [en] (X11, U; Nessus).
Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, image/png, */*.
Accept-Language: en.
Accept-Charset: iso-8859-1,*,utf-8.