Proxomitron   mir.spaceports.com/~ptron/ or proxomitron.tripod.com

I'm a very basic Proxomitron user so this is a very basic intro to Proxomitron. If you don't have it installed, it's unlikely you'll understand anything much of what's said here. It's small, it's great, so go get it and fool around with it. Version 3b and Version 4 beta have different capabilities. Block Lists (like Willem's URL KillList) will only work with Version 4 beta.

Proxomitron is a powerful, configurable "local proxy" type web filtering program. While it has a learning curve, it's useable "out of the box" and new users can add more functionality simply by checking a few more boxes off or merging new filters into their defaults. It's free with an optional registration ("You can use the program as often as you like for as long as you like. [...] To support the program you can optionally "register" it by purchasing any album by Shonen Knife and emailing me your impressions.")

Chaining Proxomitron: To use Prox with other proxy programs like A4Proxy, Junkbuster, and WebWasher, see the Chaining Proxy Programs page.

OS: Win 9x, 2K, & NT. CounterExploitation's apps list cexx.org/apps.htm says it runs in Linux using Wine www.winehq.com.

Version 4 beta: mir.spaceports.com/~ptron/beta.htm or proxomitron.tripod.com/beta.html

Highly recommended! The ability to create lists in v4beta makes sharing lists (like we do with the hosts file) simple. By default, v4beta comes with a few lists but up to 255 lists can be created. With Prox open, click on the Config button and you'll find the default files under the Blockfile tab. The tab title is rather misleading. Besides blocking all sorts of things, lists can give permissions to favorite or trusted sites to allow what might not be allowed at other sites (cookies, scripts, images, etc). I've found this version to be very stable.

Proxomitron Mailing List: www.egroups.com/group/prox-list/info.html

Users must register on eGroups to join the mailing list or read the archives. Install the extra filter for eGroups pages before visiting that site (see Extra Filters section). The list used to be hosted by OneList but they were bought by eGroups (recently bought by Yahoo). SPAM from eGroups is a concern for many registered users. To avoid it, choose to receive posts by email rather than through the eGroups website and use an email reader that provides effective SPAM removal techniques.

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Installation & Set Up  

Version 4 beta will not have a Help File or extra "skins" included until it's a solid release. Use the Help File from v3b along with the text file included with v4beta that explains text matching changes and new features.

Prox v3b users who want to try v4beta without losing v3b can install v4beta into a separate directory. Copy the v3b Help File and any "skins" you use into the new v4beta Prox directory. Or v3b can be replaced with v4beta by unzipping the contents of v4beta into the existing Prox directory. Remember to save the v3b .cfg files somewhere first in case you decide to go back to v3b.

New Prox users should download both v3b and v4beta zip files (v3b is also available as an .exe with an installer but the zip is recommended). To install, just create a directory and extract the files from the v3b version zip into the directory. Then extract the v4beta files into the same directory, overwriting files as necessary. This will give you the benefit of the v3b help file and extra "skins" not yet available in v4beta.

Make Backups: Before fiddling with any config changes, make backup copies of the original .cfg files. Take it from me, you'll want them someday.

Start Prox on Startup: Create a shortcut to proxomitron.exe, then move the shortcut to the Windows Startup folder (for Win9x users, typically C:\Windows\StartMenu\Programs\StartUp\).

Set Up: Web browsers must be configured to use Proxomitron by setting the the browser's proxy option. It's easy. For directions, read the Installation and Eradication section of the Help File. To connect through an external proxy server, you'll need to set Prox to use your HTTP proxy settings. It's easy. See the External Proxy Dialog section of the Help File.

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Proxomitron And Zone Alarm  

When starting Prox for the first time, Zone Alarm will ask if you want to allow it be a server. Does it need server permissions? It depends on who you ask. I've never given it server permission, either local or Internet, and it works just fine. I only give it connect permissions. It's a local proxy, not a remote proxy. Try it without server permissions and if it works, there you go. If not, start by giving it the least permissions and work up till you find the point where it functions like it should.

Directions for chaining Prox with WebWasher under Win 9x/2k with ZA and ZAPro installed can be found on the Chaining Proxy Programs page.

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Default Filters - Quick Tricks  

The Help File section "HTTP Header Filters" has info on some of the filters under the Headers button and the section titled "A hitchhikers guide to the default filter set" has descriptions of some of the Web Page filters. Prox v4beta has some new filters that aren't covered in there but should be self-explanatory.

Lots of great filters are included that aren't active by default. Look through the filters provided under the Web Page and Headers buttons and check off choose what suits you. Here are a very few examples of what can be accomplished just by checking a few boxes in the Web Page filters section:

Banner Blaster and Banner Replacer: By default, the Banner Replacer is checked. To replace banners with transparent .gifs instead, uncheck the Banner Blaster boxes and check the Banner Replacer box.

This filter can be edited so that the replacement gifs won't have a blue border around them or you can choose to use your own .gif image. With Banner Replacer highlighted, hit the Edit button and in the bottom "Replacement Text"section:

To remove the blue border: Change border=1 to border=0.

To substitute a .gif of your choice, place the gif in the Prox directory and change:

src=\dclear.gif to src=\dyourpic.gif (Note: Add your picname following the \d, don't remove it.)

Hide Browser's Referrer from JS: "The "referrer" is by far the most revealing data your browser sends out. By looking at referrer lists webmasters can tell not only the site you visited last, but if you clicked a link from email or a page on your hard drive, possibly more personal information as well! Note this is normally revealed in a HTTP header named "Referer" but JavaScript can be used to grab this information as well."

This filter can be edited to send back any URL you want. With the filter highlighted, hit the Edit button and in the bottom "Replacement Text"section change the URL to whatever you like.

Kill Off-Site Images: This will kill alot of junk from third party trackers.

iFrame/iLayer to link: This will kill alot of "rich media" ads. Third party Flash, Shockwave, RealMedia ads are typically wrapped in iFrame tags (see the L90 Ad Specs page for an example).

Un-prefix URLs: This stops tracking by removing the forwarded url sometimes included when clicking links on a page. It can also help stop tracking on searches done by some search engines.

Kill Meta Tags That Prevent Page Caching: Sites force page refreshes just to serve up new ads, even though page content hasn't changed. This will put an end to that. The reload or refresh button works if you need to check for new content.

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Extra Filters  mir.spaceports.com/~ptron/newfilters.html or proxomitron.tripod.com/newfilters.html

Users can write their own filters or pick some up at the User Created Filters page linked above. Filters kept there include ones for Web Bugs and FavIcons. Check 'em out. (Note: The Web Bugs filter only handles images size from 1 to 3 pixels but I feel better having it installed. It replaces them with a transparent gif so that, in the case of spacers in that size range, page layout is preserved. However it will also replace smaller images on pages with a transparent gif, eg: buttons that are 1 to 3 pixels in size.)

Some of the blocks provided by these filters are already included in the default .cfg of v4beta. Some of these extra filters will not work with v4beta without some small changes. Trial and error is the name of the game.

Downloading and Merging Extra Filters

I've found it easiest to create a new directory named Filters under the Prox directory and store extra filters there. I can easily see which ones I've installed and they're easy to find when I update Prox, so I don't have to download them again.

Download: Click the link while holding down the shift key and save the filter as a .cfg file into the Filters (or preferred) directory. Some browsers will want to save it with these as .cfg.txt files. If this happens, just rename them and chop off the .txt from the end. If you'd rather not download, just click on the link, then copy and paste the filter into notepad and save it as a .cfg file.

Merge: Open Prox from the system tray icon and choose "file" then "merge config filters." Browse to the folder where the new filter was saved, highlight it, then hit the "Open" button. The filter will be added and the window will close. Choose "file" and then "save default settings" to save it permanently in your default configuration.

Check: The filter should be found under the Web Page button or the Headers button, depending on what type of filter it was. Check that the new entry with the name of the filter you installed is where it's supposed to be.

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URL Kill Filtering And Hosts  

The following benefits apply to the URL Kill filter (v3b) as well as use of the URL Killfile list (v4beta). For hosts file troubleshooting, see the Benefits/Restrictions and FAQ sections of Gorilla's GDS Hosts Site accs-net.com/hosts/ and Bruce's Controlling DNS Lookup Sequence www.pacificnet.net/~bbruce/forcedns.htm page.

1. Some users can't use the hosts file (some severe slowness with some Win 2k systems involving services and other reasons) and remote proxy users can't use hosts. In these cases, using the Prox URL Kill feature provides protection otherwise not available.

2. Netscape Users experience "hang" when using the hosts file. This can be resolved by using eDexter or Tiny Web Server or by using the Prox URL Kill feature.

3. As Proxomitron filters at the HTTP level (v4beta adds HTTPS capability) while the hosts file blocks many types of protocols, using both the hosts file and the Killfile List is recommended when possible. "This doesn't cause double duty. Everything that Proxomitron blocks will not be sent to the hosts file for a DNS lookup." (Bruce)

4. Willem explains the other advantage of using the Killfile list in conjunction with the hosts file: "Due to the wildcards minor hostname changes and the addition of some new servers will have no effect on the effectiveness of the block file, whereas the Hosts file needs to be updated frequently to reflect any changes. So, although the block file is based on the Hosts file, the wildcard feature provides an extra defence. It anticipates part of future changes."

5. Restrictions on the hosts file don't apply to the Prox URL Kill feature. Wildcards allow it to block ads without blocking an entire site and it can be used with IP numbers. Examples:

http://207.218.316.23/pic.jpg or http://www.someplace.com/xyz/pic.jpg

Server information is needed to create a Block List for these types of servers. Any server info received will be shared for block lists for other programs (like Bruce's WebWasher Project: www.pacificnet.net/~bbruce/workshop.htm).

Please send these types of servers to Willem at: mailto:[email protected].

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URL-Killer (v3b)  

From the HTTP Headers section of the Help File: "The URL-Killer uses the connection killer \k option to block unwanted URLs. When a URL match is made, the remote web server won't even be contacted."

Under the Headers button, find the URL-Killer: kill -a-URL (out) box. Click on the filter to highlight it, then hit the Edit button. You'll find something like adex*flycast|*burstnet.com has been entered by default in the URL match section. This wildcard expression will block any URL beginning with adex that contains flycast at some farther point along in the URL. It will also block burstnet.com and any URL ending in burstnet.com, for example: ads.burstnet.com, www.burstnet.com.

To block additional URLs, create wildcard expressions or add URLs themselves, separating each with a pipe [ | ]. Using wildcards requires getting familiar with Prox's text matching language. See the Filter Creation section of the Help File.

Or use Prox v4beta instead and use Willem's Kill File List. Prox v4beta redirects the URL Match section of the Edit window to the AdList (URL killfile.txt). It's a much simpler solution!

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Willem's URL KillFile List (v4beta)  

Willem created and maintains this list from Stephen Martin's Hosts File List. It is a variation of the default URL Killfile.txt in Proxomitron. He has also provided all the info in this section and the page illustrating how to install the Killfile. Thanks!

The current file is version 2000.09.12:

Download:  WillemList.zip (unzipped, 5980 bytes)  or  View in plain text:  WillemList.txt

Install: See Installation Of Willem's Killfile for illustrated directions. This method leaves the original URL Killfile.txt unchanged.

Tip: Proxomitron can also use Junkbuster blockfiles. There's one at: waldherr.org/blocklist. Save it as Junkbuster.txt and place it in the Prox directory. This way you can choose out of three blockfiles: the original URL killfile, WillemList or Junkbuster.

Tweaks: Entries in WillemList.txt (and in any Prox URL Killfile.txt) may be deleted or remarked out with a number symbol (#) to stop the block against them. The use of wildcards in Prox blocklists requires users to get familiar with basic syntax.

Example: You want to get to www.remarq.com but it's blocked. Open Prox, hit the config button, and under the Blockfile tab, highlight the Adlist (URL Killfile list) and hit OK to edit the entry for remarq:

Updated: Sept 27-00

Quoted excerpts are © Scott Lemmon unless otherwise noted.

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