Turning Network Free-Riders' Lives Upside Down

An anonymous reader writes "You discover that your neighbours are using your unsecured wireless network without your permission. Do you secure it? Or do you do something more fun? A few minutes with squid and iptables could greatly improve your neighbours' Web experience ..." Improve is a relative term, but this is certainly gentler than certain other approaches.

Goats

[ajiva (156759)]

I'm surprised the guy didn't send every link to goats.ex... He was being way too nice.

Re:Goats

[Roody Blashes (975889)]

If you don't secure a wireless connection that spills onto other people's property, why shouldn't they use it until told otherwise? You could argue that you're not really encroaching, but I guarantee you that's not true. There's another network near us that was too weak to always show in the list of nearby nets, but was just strong enough to cause intermittent signal pollution until one day I happened to move the router to get at something else, and noticed it next time I connected.

If you let your signal spill over onto other people's space, too bad.

In fact, I wouldn't be mad if someone were using my connection without my approval unless they were encroaching on my space to do it. In fact, I only secured it because of bandwidth concerns and the potential for other people to use it for illicit purposes.

Re:Goats

[trewornan (608722)]

I chose to leave my wireless network open so that if someone nearby needed a connection it would be available for them. If someone was to impose an unreasonable load on the network I might do something about it but so far (12 months) I've had about half a dozen people connect and download relatively small amounts of data - my guess is they were checking email. Why would I object to that? No . . . why would *you* object to that? The way I see it it's a chance to do something nice for other people, why not get yourself some good karma.

Re:Goats

[generic-man (33649)]

I've lived in two places where I set up my access point with no encryption. In both places, I've fired up iTunes to see someone else sharing music on my LAN. This didn't bother me until I read the name of the share: "(name)'s LimeWire Tunes."

I don't mind if people want to check their e-mail on my WAP. I do mind when they idle on file sharing services, using lots of bandwidth and exposing me to potential legal liability.

It's a shame that I have to protect my router somehow, especially because one of my devices (a Nintendo DS) doesn't support WPA at all.

Re:Goats

[Starker_Kull (896770)]

It shouldn't be too hard to set up some fixed IP addresses for your home machines, and let "guests" use a different IP range, for which you have implemented port blocking for all but 80, 25 and a few others for https and sending email, if you wish.

Re:Goats

[jasen666 (88727)]

That's exactly what I've setup at my wife's salon, where she has an open wireless for her customers. The office computers have full internet access, any wireless guests have their ports limited to the basics. The cheapy D-link router had this capability built-in, making it a no brainer.

Re:Goats

[ShawnDoc (572959)]

Your router is giving them permission to associate, is providing them with an IP address, and is allowing them to pass traffic. Heck, I'm guessing your AP is even broadcasting its SSID and telling people its available for them to connect to. When the client associates it acts just like a web page request, it says "Hey, can I connect here?" and if your router replies with a "Sure thing!", then as far as I'm concerned you've given them permission to use your network. If you don't want strangers using your Internet, you've got TONS of options, turn off DHCP, use WEP, use WPA, limit access only to those MAC addresses you approve, turf off SSID broadcast. Obviously some of these offer better security than others, but ANY of these will prevent a casual user from using your network.

Re:Goats

[b0bby (201198)]

Yeah, that's what I do too. My neighbors also have open access points mostly. I check the logs every so often, but I've never seen anyone but me having connected. Still, if someone wants to check their email, it's there. I don't have a problem using open points to check mail while I'm travelling, might as well return the favor. I'd lock it down if someone were leeching 24/7, but I don't see any of my neighbors doing that.

Re:Goats

[ShawnDoc (572959)]

You've got two problems you've overlooked. If someone uses your connection for illegal activity (downloading Meet the Fockers, kiddie porn) it will be your IP address that the RIAA/MPAA/FBI will trace. Good luck convincing them it wasn't you. You might be able to do it, but it will take up time and money (lawyers) to clear your name. And in the case of kiddie porn or other criminal act, expect every computer, PDA, and cell phone in your home to be confiscated to be analyized for incriminating data. The second problem is you are allowing strangers access to not only your Internet connection, but also your LAN. I have multiple computers and put files in shared folders so I can access them from different machines. I don't want some strange to have access to those files, or worse, have their computer be infected with a worm/virus that propogates across the network.

Re:Goats

[element-o.p. (939033)]

Unfortunately, not everyone is as kind (or patched/anti-virus'ed/etc.) as your neighbors are.

I spent three years as an abuse admin at an ISP, and spoke with a number of customers where the only likely culprit for an abuse complaint was someone "borrowing" their Wi-Fi connection (nmap [insecure.org] is a wonderful tool for finding likely infections/file sharing clients). In almost all of these cases, securing the Wi-Fi access point made the problem go away.

It's possible that my customers were lying and that they just latched on to the Wi-Fi excuse to get me off their backs, but after three years, it (usually) wasn't too hard to tell when someone honestly had no clue and when they were covering up :)

So *that's* why I object to people using my Wi-Fi without permission.

Re:Goats

[StikyPad (445176)]

That's why whenever I go to the park, I always run toward the large flocks of pigeons while flapping an umbrella and crying out "PAKAW! PAKAW!" Sure, it's a little embarrassing, and the people who get droppings on them in the ensuing mass migration get a little upset, but if it saves even one pigeon, then it's worth it.

Unfortunately, I believe it's only scaring them away from people who charge them with umbrellas while screaming which, in my experience, is not a significant number. I fear I'll soon have to resort to more drastic measures, like holding out some popcorn and then cold-cocking the first sonofa dove that makes a lunge for it. Of course I'll tell them it's only for their own good, and it hurts me more than it hurts them.

Re:Goats

[sammy baby (14909)]

If you don't secure a wireless connection that spills onto other people's property, why shouldn't they use it until told otherwise?

Conversely, if you find someone else's unsecured wireless network, why would you complain if they decided to flip all the images?

Liability?

[lecithin (745575)]

What are the odds that a neighbor would use your network and then sue you for the content that your are sending to him?

Re:Liability?

[`Sean (15328)]

What are the odds that a neighbor would use your network and then sue you for the content that your are sending to him?

Yeah, ailurophobia is a bitch.

Re:Liability?

[darkonc (47285)]

If you redirect a minor to goatsex, you might be in trouble.

If, on the other hand, you simply mangle the images that (s)he's looking for, then you could say that you're protecting the kid from nasty content.

It's not like you have a contractual responsibility to deliver something that (s)he never asked or paid you for.

It's not their fault...

[nick_davison (217681)]

How can you blame people for connecting to a wireless router with the ID "Free Porn"?

Granted, my neighbors didn't intentionally set their router up with that ID but they did leave it unsecured with the default password for the admin account. It was simply the neighborly thing to do to change their ID and resecure it with a new password (that, admittedly, they didn't know).

Should be legal

[gilroy (155262)]

In our topsy-turvy legal system, it might not be. :( But it should be. The nieghbors have no right to expect anything so they should have to just accept whatever the router sends them. As allegedly was said by Truman Capote:

The trouble with living outside the law is, you put yourself beyond its protection.

Re:Should be legal

[edmudama (155475)]

IANAL, but your machine is manipulating those bytes as they go by, and therefore you're tampering with their communications which may be legally protected.

As funny as this might be, I don't see it as being worth the potential liability. If the DMCA can attempt to outlaw drawing on your CD with a sharpie, then you could get in trouble for just about anything.

Could just watch

[MECC (8478)]

Could just watch their traffic, and when they try to bid on ebay, just slow their traffic down, then out bid them. They'll rue the day they tried to outbid 'yourneighborfromhell' on ebay.

Missing the point, I think

[truedfx (802492)]

You discover that your neighbours are using your unsecured wireless network without your permission.

If your wireless network is unsecured, permission to use it is implied, and there are operating systems that will automatically use such networks, are there not?

Re:Missing the point, I think

[squiggleslash (241428)]

No, it's not implied. As the law stands, it's illegal unless you get something more explicit in terms of permission. Yes, illegal. Yes, people have lost in court. No, not civil court, criminal.

(And it makes sense that no implied permission is given by simply having your router be unsecured, given "unsecured" is the default configuration of most off-the-shelf routers.)

It really isn't an issue in practice. If you want to use someone else's network, all you have to do is ask them. With 802.11, you're close enough to be able to do so. There's no reason not to ask, other than knowing that "no" is likely to be the answer. And I think that's why people tell themselves the myth that somehow they have implied permission simply because the "door" was left unlocked.

Re:Missing the point, I think - absurd.

[4e617474 (945414)]

What you are saying is that, unles I put a tarp up around my garden, everyone has a right to use it.

No, actually we're saying that if your garden pelts us with carrots and peas as we walk past on the public street, we're at liberty to catch them and consume them. Only if you place anti-vegetable-flight netting around your garden (or stop planting vegetables that lend themselves to comparison to an unsecured WAP) does it become incumbent upon us to behave as good citizens.

Hey! Analogies are fun! Somebody compare Internet privacy law to hunting and fishing licenses!

Obligatory Bash.org

[Ryan Stortz (598060)]

One of my all-time favorites. :)

(Mootar) morons.
(Mootar) these people who live in my apartment complex are connected to my wireless
(Mootar) they must think they're super-cool hackers by breaking into my completely unsecure network
(Mootar) unfortunatly, the connection works both ways
(Mootar) long story short, they now have loads of horse porn on their computer

http://bash.org/?202477 [bash.org]

Re:Obligatory Bash.org

[Kjella (173770)]

Now I don't know which channel that was said in.... but I'd be slightly concerned that he just happened to have "loads of horse porn" to upload to their computer.

Stealing?

[SecurityGuy (217807)]

It's as much stealing as sending the signal into their home is trespassing.

I think you just shake your head at your failure to secure it in the first place, decide if you care, and if you do, lock it down.

Funny way to deal with it, though.

Can you imagine the tech support calls?

[Tackhead (54550)]

Substituting everything with Goatse or Tubgirl (Goatse was already done with airpwn [evilscheme.org] at DEFCON 12) would be funny, but Joe Sixpack would call tech support, and they'd all shrug it off saying he'd been cracked with some sort of virus.

But can you imagine Joe Sixpack trying to explain to Pradeep that all the images in his web pages were being displayed upside-down (or better yet, blurry, or upside-down and blurry!), while all the text in the very same web pages was being displayed upside-right in crystal clarity?

Joe Sixpack probably doesn't know the differences between images and text. Pradeep would hear the word "upside down" or "blurry" and immediately think it was a hardware problem.

It'd probably take any of us half an hour to convince a second-tier tech that we weren't trolling him, never mind Joe Sixpack.

I'd give my left nut to hear the support calls on this. (Particularly as I'm pretty sure that those of you in tech support have no use for my left nut. :)

Re:Can you imagine the tech support calls?

[nizo (81281)]

I'd give my left nut to hear the support calls on this.

Maybe you can, if your neighbor is using your network connection to fullfill all his VOIP needs.

Re:Can you imagine the tech support calls?

[nizo (81281)]

By the way if this works you can keep your left nut; it would be too awkward explaining to people what I just got in the mail.

Re:Can you imagine the tech support calls?

[dilvish_the_damned (167205)]

I just checked out tubgirl. I think they could sue you. If I were on the jury they would win. Its just too inhumane and unusual to do to someone.
I am going to go see if I can't salvage what remains of my ruined day.

getting biblical on the neighbours

[spyrochaete (707033)]

When my neighbour mooched my wireless I had a little fun with Cain & Abel [www.oxid.it]. I got some good recipes from their private documents. Romano cheese really is better than parmesan on spaghetti!

You can have a lot of phun with this all-in-one cracker suite. Hell, if my neighbours had a MS-SQL server or Cisco switch I could have 0wned those too!

Feh

[NitsujTPU (19263)]

Improve is a relative term, but this is certainly gentler than certain other approaches.

I don't really see the point. It's funny as a practical joke. In terms of protecting your network... why not just secure it instead?

Secure?

[TCM (130219)]

He already uses the notion of trusted and untrusted networks, yet he makes no effort at all to prevent 1) spoofing 2) non-IP protocols 3) access from the untrusted network to his trusted network.

If you plan to take on others, make sure your own stuff is secure.

You can't steal unprotected Wifi.

[insomniac8400 (590226)]

It's impossible to steal unprotected wifi. If you leave your connection unprotected, that means you are purposely sharing it. Although flipping the pictures upsidedown is pure genious.

Re:You can't steal unprotected Wifi.

[realmolo (574068)]

Hey man,

I think that someone is redirecting your requests through a proxy server that randomly inserts the letter "o" into the word genius.

Moran.

HuH?

[bennomatic (691188)]

If I leave my bike outside unlocked for 10 minutes, am I giving explicit permission to anyone who sees it that they can take it? No. Am I allowing it to happen through negligence? Sure, but call it what it is; it's still stealing, or at least trespassing.

Even something as amorphous as bandwidth is a limited resource. To paraphrse the head of the commerce committee, an open wireless connection is not a dump truck you can just load up with as much as you like; it's a tube!

Sure, if you want to make sure nobody uses your tube, you should protect it. But just because you don't doesn't mean you're giving explicit permission. If I leave my bike on my front lawn without a lock and someone steals it--even if they give it back before I notice it was gone--it's still theft.

Understanding the Approach to this

[blantonl (784786)]

For those that are struggling to understand how the author of this article is accomplishing his approach, here is some further information.

The author obviously has a Linux server in his house, that is running DHCPD [freeshell.org]

To selectively send some clients to some locations, and others to the normal internet, he assigns an IP address on a different network to clients that don't have MAC Addresses [wikipedia.org] that he knows about.

Forwarding on to sites of his choice is done by using IPTables [netfilter.org], which is a utility that allows you to configure the packet filtering components of the Linux TCP/IP Stack. In this instance, the Linux box is just functioning as a firewall, and he is selectively sending requests from certain IP addresses to different hosts of his chosing.

Finally, the Up-side-down and blurry-image conversions is accomplished by sending page requests from those before-mentioned IP addresses to a proxy server, which in this case is Squid [squid-cache.org] - and then allowing the proxy server to run a script which calls an ImageMagick [imagemagick.org] command called mogrify [imagemagick.org] which allows you to resize an image, blur, crop, despeckle, dither, draw on, flip, join, re-sample, and much more.

And that folks, is the rest of the story.

Re:Understanding the Approach to this

[hab136 (30884)]

$url = $1;
system("/usr/bin/wget", "-q", "-O","/space/WebPages/images/$pid-$count.jpg", "$url");

This line gives me chills. He's passing a completely unsanitized input (the bandwidth thief's URL) to a system() function.

At least he didn't concatenate everything so that system() would run the entire string as a shell command.. then simply adding a semicolon or pair of backticks to the url would cause the system to run any command the attacker liked, including deleting all files squid has access to and running a custom backdoor. There are a lot more local root-escalation flaws than remote.

Even without the shell character vulnerability, who knows what kind of failures you can induce out of wget given the right parameters. He should sanitize the URL before passing it out.

There's also the possibility of a vulnerability in mogrify, given the right corrupted image file to work on. Mogrify should be run in a separate user account that has no access to anything other than the input file.

Never trust your input, especially from an already-admitted evildoer.

Yes, I'm paranoid - I work in information security. :)

Other ideas

[necro2607 (771790)]

This is hilarious! My coworker and I just sat here laughing and coming up with other great ideas for having fun with hijackers' browsing experience:

-Occasionaly replace images with random google-image-searched images
-Translate any text on a web page on the fly into some very English-like language but different enough to make the pages impossible to understand
-Translate text on the fly into languages with non-arabic characters
-The obligatory replacing all images with random porn images
-Keep the first/last letters of every word the same, but jumble the letters in between. You have seen this site [cam.ac.uk], haven't you? ;)
-Invert the colors of all images on the web pages
-Convert all graphics to grayscale, or 16-color

etc. etc.

The possibilities are obviously pretty extensive... I think after hearing about this I'll be a little more careful with my usage of other peoples' wireless networks! ;)

This is what SSH tunnels are for

[tdvaughan (582870)]

I just moved into a new flat and as it took a while to get internet access, I had to "steal" someone else's wireless (although I take the position that if they want to beam radition through my property, I can do what I want with it). I took the strongest unsecured signal but because (being a sneaky bastard) I know what I would do if I ran an unsecured wireless access point I just tunnelled everything through an SSH tunnel to a proxy at work.

Assign invalid address or route to localhost

[MImeKillEr (445828)]

If you're so intent on leaving it open, I'd suggest just getting their mac address and assign it back to 169.254.x.x or 127.0.0.1. That way, if they actually do anything illegal, its not tracked to you.

You're just flipping webpages, right? What's to stop them from getting on a P2P network and sharing/downloading files? What's to stop them from visiting illegal porn sites?

Doing this to them will just make their internet useless. Not as funny, but safer IMO.

Another thought: Is there some way to randomly route their requests to a totally different webpage? Say they want to go to Google, etc. Is there some way to redirect their request to a randomly-generated (but real) URL? I'd suggest something in a foreign country.

Open Networks

[Elektroschock (659467)]

sorry, I am a supporter of open networks. I think the freifunk olsr-protocol approach of open wireless networks [freifunk.net] is best. We don't need internet providers and we don't need internet provider which leak our communication data to the governments and endanger the freedom of the net. The net should be a net and wireless technology is great for the creation of a real P2P internet.

I cannot support any action against people who use your network. It is against my understanding of hacker ethics. When you don't like it then close your network. But no childish games please.

I may even say that I find it unethical to exclude your neighbours from using your network but I respect your opinions. When your network is open it means: Be free to use it. Not: You can use it but I will fuck up or intercept your communication.

Except

[geekoid (135745)]

by leaving it open he is inviting other people to connect.

Some computer says to the router "Hey, can I come in?" and the router says "Sure". Now, the moment you put something up, like needing a password, then you are no longer inviting people in.
Computer says "Hey, can I come in" router says "Sure, if you know the password."
Or you can encrypt it
Computer says "Hey, can I come in?" the router says "KE*jd7638JDEJE*834899(&^&#nd&#&bd*e#"

blurry-net

[Sloppy (14984)]

At first, I thought there were way too many screenshots. I mean, ok, we get it. But then at the bottom of the FA, it pays off. After the dumb kitten and upside-down stuff (where they know someone is fucking with them) we get to the treasure: blurry-net. That's subtle and I love it. The ideal prank for the proverbial Man In The Middle would be to do things to confuse the endpoints, not merely annoy them.

The next step is to spy on them and see what websites they visit, and then insert some fake content one day. For example, if they use it to read CNN, insert a casual story about a nuclear weapon getting used in the Middle-East or South Asia, or a story about the president of USA selecting a new vice-president due to the assassination last week ("What?! I didn't hear about that!"), or the CDC in Atlanta is investigating the recent rash of improbable claims about the dead returning to life to feast on the flesh of the living, etc. If they visit Slashdot, then the jig is probably up, but maybe it would be great to have a story where a security study found Windows98 to kick OpenBSD's ass and then a bunch of comments where everyone agrees that the findings pretty much match their own experience, along with complains about "how is this news for nerds?!"

Certainly one could be *far* more evil than this..

[by Anonymous Coward]

Network freeloaders put themselves at risk... It would be trivial for someone to set up a "Free Internet" wireless AP and then run phishing attacks, sniff IM conversations, e-mail, etc. Considering how little the average internet user even pays attention to SSL, one could very easily imitate a bank, ebay, paypal, etc... One should certainly think twice before freeloading on someone's wireless network - and if you do, at least tunnel your connection securely (even socks5 over an SSH tunnel, etc)..

Frame this

[Midnight Thunder (17205)]

I suppose you could also add a frame to every page and then sell advertising space. Since you probably know a bit about your neighbour it is much easier make targeted advertising. Of course you could always make the top frame read:

      "This is borrowed bandwidth. Have you thought about getting your own connection."

Oh and make sure it is flashing. Actually you could make it so that the whole content flash. Now that would be annoying.

Hello, tech support?

[jpellino (202698)]

Upside down is cute, but blurry is just too fantastic.
You know they were on the horn to the vendor after punching every monitor control and several loud screaming matches and an expensive service call for a monitor that then worked just fine on the bench...
As a webmaster I can now say April 1 just got very far away...

Re:It could be worse...

[andrewman327 (635952)]

I'll just have to turn my monitor upside down! Oh crap, I'm using a laptop.

Re:Trying to make others feel as stupid as you wer

[SoTuA (683507)]

By leaving it open in the first place to be stolen, you've shown your dumb.

Calling someone on slashdot dumb - mostly free.

Making a dumb mistake while calling someone dumb - priceless.

Sniff, sniff.

[bigtallmofo (695287)]

i'm far from expert on the subject, but if you are on the same subnet , sniffing should be trivial.

Sniffing has nothing to do with subnetting. It has very much to do with the hardware that connects you. If you're both connected to the same hub, you can see all of each other's traffic. If you're both connected to the same switch, you can't.

Note that as a Slashdot comment, this an extremely simplified explanation and not a complete picture.

Re:What's the POINT?

[Ant P. (974313)]

That was a terrible poem.