Results 1 to 5 of 5

Thread: Interesting anti-spyware campaign

  1. #1
    takebackour.net@gmail.com Guest

    Interesting anti-spyware campaign

    Get informed about PREVENTING spyware/adware BEFORE it happens - not
    cleaning it up after it after-the-fact...

    Visit http://www.takebackour.net to learn more. When we all do our
    part, it becomes in-effective.


  2. #2
    David Arnstein Guest

    ADVERTISING: Interesting anti-spyware campaign

    This web page is simply an advertisement for a commercial software
    product. I call SPAM.

    What this product does, a pair of free products do as well. Google for
    DNSKong and eDexter.
    --
    David Arnstein (00)
    arnstein+usenet@pobox.com {{ }}
    ^^

  3. #3
    Borked Pseudo Mailed Guest

  4. #4
    Vanguard Guest

    Re: ADVERTISING: Interesting anti-spyware campaign

    "David Arnstein" <arnstein@panix.com> wrote in message
    news:en6foa$8af$1@reader2.panix.com...
    > This web page is simply an advertisement for a commercial software
    > product. I call SPAM.
    >
    > What this product does, a pair of free products do as well. Google for
    > DNSKong and eDexter.



    From http://www.pyrenean.com (where are both DNSKong and eDexter):

    "With DNSKong on duty no application can connect to a domain name that
    matches your filter rules."

    That presumes that the application making the connection or the HTML
    code sent your browser uses IP *names* to point at the targets (for the
    images). What would stop the app or HTML code from using IP
    *addresses*? DNS only gets used if an IP name is used. If an IP
    address is used, there is no DNS lookup so DNSKong which is a local DNS
    server would get bypassed. This is also how a hosts file gets
    circumvented. If the request goes to an IP address then there is NO
    lookup. Guess you'll have to take care of those in your software
    firewall's IP blocking feature but that is really only useful for static
    IP addresses. An HTML web page could reference IP addresses (not IP
    names) and those reference could change. In fact, they could change on
    every retrieve of the web page provided the spammer has enough of them
    to cycle through using a server-side script that compiles the web page
    that gets profferred to your browser and which uses IP addresses instead
    of IP names.

    Blocking by DNS for IP names is flawed but it is probably mostly useful,
    just not wholly useful. Also, it would be nice if DNSKong used regular
    expressions instead of just matching on substrings. I might want to
    block "*.\.admt\.com$" but not on "www.loadmt.com.nl" (which just
    "admt.com" would end up blocking). There was no info at their site on
    just what you specify in their named.txt file or how DNSKong uses those
    entries (as exact match, as substrings, as anchored substrings on right
    or left of parsing points, etc.).

    One problem with blocking, say, ad images when visiting a web page is
    their server may use them as web beacons. You are blocking the image
    file from some other domain but that site may check if you downloaded
    the image. If you don't download the ad image, they won't present their
    web page. Fair enough. It's their web site. So just realize that
    blocking images, like ads, may result in you not being to visit or view
    a web site. In that case, you might as well block that site instead of
    just the images. Also, many use follow-through links. The image comes
    from the same domain, and maybe even the same host, as the rest of the
    web page. Their server then gets the image from wherever is the ad
    source. If you block the domain for the image, you've also blocked the
    domain for the web page. Fair enough. It's their web site.

    Rather than blocking the request to retrieve and image which could
    render a web site unviewable or inaccessible is to block the image that
    got yanked. That is, the server sees you yank the image but it is in
    your block list so it simply doesn't get to the browser. Instead a
    substitute image shows up, like "Image blocked by <productname>". This
    is probably how you would use a proxy through which your browser would
    connect. You don't block any requests for web content. You block what
    web content ends up delivered to your browser (or whatever application
    made the request). This is very similar to how I handle cookies.
    Rather than block a domain from saving its .txt cookie files on my
    computer which often results in a site refusing to load or function
    correctly (i.e., you must have their cookie to use their site), I allow
    ALL cookies but force them to be per-session cookies (i.e., they get
    deleted after the browser session ends). For domains that are allowed
    to leave their cookies, they get whitelisted. All other domains are
    allowed to leave their cookies (I do still block 3rd party cookies,
    however) so I don't have a problem while I'm at their site. When I
    close my browser, all the non-whitelisted cookies get purged.
    Similarly, I'd rather let a web site think it delivered all its content
    so it functioned correctly and didn't know that some of its content got
    filtered out so it never showed up in my browser. They haven't a clue
    as to what I actually saw.

    With DNS (or URL) blocking, they can figure out if I blocked their ads
    simply because the IP address that connected to them doesn't send back
    the requests for the image links. I'd rather be stealthy than obvious.
    Anything available (preferrably free) like I describe? There are some
    products that provide URL filtering (I have some) but they do blocking
    of the request. The web site can detect that you aren't retrieving some
    of their content (and can alter or refuse content). I don't want them
    to know. I want to retrieve it so they think that I got it all but that
    doesn't mean that I want to SEE it. In fact, while I may retrieve their
    content (that is eventually blocked as downstream traffic rather than
    preventing upstream traffic to request their content), there need be no
    slow down for the browser since the proxy would be doing the yanking and
    could even abort immediately after the retrieve starts.


  5. #5
    David Arnstein Guest

    Re: ADVERTISING: Interesting anti-spyware campaign

    In article <GLqdnWAB_YnRoArYnZ2dnUVZ_smdnZ2d@comcast.com>,
    Vanguard <vanguard.news@yahooNIX.com> wrote:
    >That presumes that the application making the connection or the HTML
    >code sent your browser uses IP *names* to point at the targets (for the
    >images). What would stop the app or HTML code from using IP
    >*addresses*? DNS only gets used if an IP name is used. If an IP
    >address is used, there is no DNS lookup so DNSKong which is a local DNS
    >server would get bypassed. This is also how a hosts file gets
    >circumvented. If the request goes to an IP address then there is NO
    >lookup. Guess you'll have to take care of those in your software
    >firewall's IP blocking feature but that is really only useful for static
    >IP addresses. An HTML web page could reference IP addresses (not IP
    >names) and those reference could change. In fact, they could change on
    >every retrieve of the web page provided the spammer has enough of them
    >to cycle through using a server-side script that compiles the web page
    >that gets profferred to your browser and which uses IP addresses instead
    >of IP names.


    You are right. The more robust blocking technique is to block (numeric)
    IP addresses. I used to do this too, by typing out a long list of IP
    addresses into the config file of my little Cisco router. The disadvantage
    of IP address blocking is the amount of typing you have to do. I will
    use doubleclick.net as my canonical example. Suppose that you wish to
    deny access to all of doubleclick.net. You would have to do some research
    to find out all of the IP address blocks that doubleclick.net claims as
    its own. The list of address blocks will change week to week, so this
    is quite a job. I know, I used to do this.

    The alternative is blocking by domain name, and that is what DNSkong
    does. Personally, I use a different program "dnrd." Personal preference.
    With this approach, I can block (imperfectly, I admit) all of
    doubleclick.net with a single line in my dnrd config file. I don't have
    to do any maintenance on that line either. Whatever doubleclick does to
    its server farm, it stays blocked.

    What would be really great is if someone devised a way to *automatically*
    list all of the address blocks owned by doubleclick.net. If a piece of
    software could do that for me, I could run it every night, and write a
    script to transform the output of this program into a router config
    spec. I wish that I knew how to write such a program. Any suggestions?

    Currently, I am blocking 541 domains with dnrd. These range from ajeeb.com,
    to doubleclick.net, to zrap.zdnet.com. There is no way that I could
    maintain lists of IP address blocks for all of these domains. It is just
    too much work.

    Coming back to the original (somewhat spammy) poster. I briefly looked
    at the cited web page, and it seemed like the product he is pushing is
    just another DNS relay program, like DNSkong or dnrd. If I am wrong
    about that, please correct me.

    Any other ideas on blocking unpleasant internet addresses? I am very
    interested in this topic.
    --
    David Arnstein (00)
    arnstein+usenet@pobox.com {{ }}
    ^^

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •