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Drive-By Pharming In the Wild

An anonymous reader writes "Symantec reported Tuesday that the first case of drive-by pharming, in which a hacker changes the DNS settings on a customer's broadband router or wireless access point and directs the link to a fraudulent Web site, has been observed in the wild. The first drive-by pharming attack has been observed against a Mexican bank: 'It's associated with an e-mail pretending to be from a legitimate Spanish-language e-greeting card company, Gusanito.com,' says Symantec Security Response principal researcher Zulfikar Ramzan. Inside the e-mail is an HTML image tag but instead of displaying images, it sends a request to the home router to tamper with it."

43 of 205 comments (clear)

  1. Pfft by Kalriath · · Score: 4, Insightful

    So, I suppose this "hack" fails entirely on any router which... well, either has a default password or (like any high end router) doesn't use HTTP basic authentication? No worries for me, my 3com is safe as houses.

    --
    For a site about things like basic rights, Slashdot users sure do like to censor "dissent".
    1. Re:Pfft by cheater512 · · Score: 2, Insightful

      My AMD X2 'router' is also immune.

      Having a real workhorse as your router improves security dramatically as well as allowing you to do some really cool things. :)

    2. Re:Pfft by WhatAmIDoingHere · · Score: 2, Funny

      So your router contains stuff you don't ever want to lose? Not quite the best idea.

      Also, the A in RAID stands for Array. RAID Array is like ATM Machine or PIN Number.

      --
      Not a Twitter sockpuppet... but I wish I was.
    3. Re:Pfft by Ajehals · · Score: 2, Informative

      Hmm, personally I prefer my routers not to have too many potential vulnerabilities, yours sounds like a nightmare from that perspective. What you are telling me is that a box on the edge of your network, a box that presumably is very open to abuse also happens to hold a huge volume of data, not too bright, even if it is just TV shows. Personally I'd grab a modest piece of hardware suited to the role and ensure it was locked down as tightly as possible.

      Just out of interest, what OS is this monster router running?

    4. Re:Pfft by spinkham · · Score: 2, Informative

      Not necessarily..
      It is also possible to change settings on a router using UPnP using a malicious flash script...
      See http://www.gnucitizen.org/blog/flash-upnp-attack-faq for details.
      Most home routers have UPnP turned on, so you're not safe just because you have a good password.
      I would assume that most 3com gear does not have UPnP, so it is quite likely that you specifically are safe.
      Of course, anyone with a security clue has been saying UPnP is a BAD idea for a long time, but it used to be client side malware people were worried about, not well formed flash on any webpage...

      --
      Blessed are the pessimists, for they have made backups.
    5. Re:Pfft by edittard · · Score: 2, Funny

      If that's the delay between posts, it's more of a craptrickle.

      --
      At the bottom of the /. main page it says 'Yesterday's News'. Well they got that right.
  2. Let me guess... L: "admin" P: "admin" by Zymergy · · Score: 2, Insightful
    1. Re:Let me guess... L: "admin" P: "admin" by Gideon+Fubar · · Score: 3, Informative

      There are 3 major combinations of default username/password comnbinations that cover the vast majority of home routers. They are U:admin P:admin, U:admin P:password and U:admin P: (that's right.. NO password.) This is true of Linksys, Dlink, Netgear, etc. With a bit of searching, you can even find this out from their very own websites.

      --
      http://www.xkcd.com/354/
  3. Captcha? by tedhiltonhead · · Score: 5, Informative

    It sounds like a simple captcha image on the router's login page would thwart this.

    1. Re:Captcha? by cheater512 · · Score: 4, Insightful

      Or maybe force users to change the password.

      Which one makes more sense? :P

    2. Re:Captcha? by Cato · · Score: 2, Informative

      Which reminds me, Netgear routers seem to redirect 192.168.0.1 to 'routerlogin.com' (owned by Netgear, but actually maps to your router normally). A somewhat dodgy design decision really as it serves to obfuscate what's happening when newbies log on to their router, which can't help them to learn more about security.

  4. Biggest Mexican Bank? by xtracto · · Score: 5, Informative

    2Wire DSL routers to point the user's Web browser to a fraudulent bank site that mimics the site of one of the largest Mexican banks.

    There is not much space to guess here, it is either Banamex or Bancomer...

    --
    Ubuntu is an African word meaning 'I can't configure Debian'
    1. Re:Biggest Mexican Bank? by nesmex · · Score: 4, Informative

      Well yes is Banamex. This attack was reported during late last year. This exploits a vulnerability in 2WIRE modems, as documented in US-CERT http://nvd.nist.gov/nvd.cfm?cvename=CVE-2007-4389
      Trend Micro has a more recent report on a variation of this attack http://blog.trendmicro.com/targeted-attack-in-mexico-dns-poisoning-via-modems/
      The UNAM-CERT, also has the "Gusanito" exploit documented (spanish only) at http://www.seguridad.unam.mx/doc/?ap=articulo&id=196
      The attack overrides the modem's password...

    2. Re:Biggest Mexican Bank? by moco · · Score: 2, Interesting

      It was banamex, and the worm modified the target PCs hosts file. It wasn't even sophisticated enough to hack the broadband router... just a .exe file posing to be a greeting card.

      --
      moi
  5. Definition? by WarJolt · · Score: 5, Interesting

    What does "drive-by" have to do with this kind of hack? Oh sure we've all logged into neighbors wireless routers and snickered because they've left the default password. Somehow I think "drive-by" part was coined by a guy who thought of exploiting unsecured wireless routers and changing DNS settings. Am I the only one who doesn't think "drive-by" applies to this kind of attack?

    1. Re:Definition? by Vyse+of+Arcadia · · Score: 3, Funny

      I dunno about anyone else, but to me it conjures up images of 90s-era Hollywood hackers. Suave guy in the driver's seat of a red car, his short, befreckled and bespectacled companion laboriously typing on a laptop while muttering things about "This is UNIX" and "His serving RAM is so unprocessed."

  6. British Telecom Home Hub by ddrichardson · · Score: 4, Interesting

    Anyone else notice that BT are taking this seriously - log on to the router's home page and it tells you they have changed the default admin password (well it will when you enter the unit's serial number as the admin password.

    --
    A thistle is a fat salad for an ass's mouth...
  7. Enough with the default passwords. by GreggBz · · Score: 4, Insightful

    If Bioware can sell $30 software with unique CD-Keys printed on the inside of each jewel case, why can't Linksys sell $40 routers with unique admin passwords printed on each manual. Or better yet, make the default password the last 6 digits of the LAN side MAC address, that can't be terribly hard to manufacture.

    Seriously, you could even honestly market them as "more secure."

    1. Re:Enough with the default passwords. by moderatorrater · · Score: 4, Informative

      Several reasons. First, it's easier to change what gets stamped into a cd than what gets set into the silicon. Second, the cd key isn't actually unique to the CD, it just conforms to an algorithm that determines whether or not the cd key fits the criteria for the software and then, when on the network, checks to make sure that the cd key was actually sold and that it's unique.

    2. Re:Enough with the default passwords. by blair1q · · Score: 3, Interesting

      Because software can pop up a box on your screen saying "go look for the sticker on the box and type the letters and numbers (and maybe the dashes or maybe not, your guess is as good as ours) you see there into this box here then click the button that says 'OK'".

      Hardware says "blink"..."blink"..."blink"... and user calls customer support, adding $10 to the cost of every sale.

    3. Re:Enough with the default passwords. by Compholio · · Score: 3, Insightful

      It would be trivial to use the LAN MAC address as the default password.
      It would also be trivial for someone to run "arp" while connected to your access point. I agree that they need to use a random default password, but the MAC address would not be sufficient.
    4. Re:Enough with the default passwords. by IdeaMan · · Score: 2, Interesting

      Using the LAN MAC address as the admin password is almost as stupid as using admin as the password.
      LAN MAC address is burned into an EEProm at time of manufacture. It is also reset to "Factory Default" when you reset the box. It should be trivial to burn a randomized default password at the same time, store it in a database and print it on the manual.
      If the customer calls up with an unresponsive router, customer service can read them the password out of the db.

      --
      They ARE out to get you simply because They are in it for themselves and they don't care about you.
    5. Re:Enough with the default passwords. by crymeph0 · · Score: 5, Informative

      It's easier to change what gets stamped into a cd than what gets set into the silicon

      Nope. I do embedded software, and write the test suite all those devices go through before being shipped to the customer. It's pretty standard to set custom stuff at that time, including the MAC ID for the unit. It would be just as easy to change the password at that time.

      Your comment about the CD key, however, is right on.

      --
      It should be illegal to say that freedom of speech should be limited.
    6. Re:Enough with the default passwords. by Lumpy · · Score: 2, Insightful

      How about simpler... the router will NOT function until you set a username and password. It routes no traffic and redirects all web requests to the "Hey stupid user, pick a username and password, no you cant use linksys, router, admin, or password."

      that way the same binary image can be used on every router. Out of the box they do not work, they requre the user to have at last 35 brain cells to get it to work and in the process will be safe from this crap.

      --
      Do not look at laser with remaining good eye.
    7. Re:Enough with the default passwords. by theeddie55 · · Score: 2, Insightful

      Or better yet, make the default password the last 6 digits of the LAN side MAC address, that can't be terribly hard to manufacture.
      that wouldn't really help, drive-by attacks access the router from the lan side anyway, so would already have access to the lan side mac address.
  8. Cold War Redux by explosivejared · · Score: 2, Funny

    Only this time it's between Mexican scammers and Nigerian ones. For years Nigerian scammers have exercised hegemony in the arena, but now Mexican scammers have upped the ante with this "pharming gap." This can only lead to a scams arms race with other nations as proxies and victims of the complex maneuvering of the two camps. As a helpless American I don't know how long I can stand being the play thing of two foreign powers duking it out for hegemony.

    By the way I'm rooting for the Nigerians in this grand campaign, at least their scams provide a laugh once and awhile.

    --
    I got a catholic block.
  9. Gusanito?? by Roadmaster · · Score: 3, Funny

    Dude, gusanito means literally "little worm"; I personally would never open an email saying "hey, you got a postcard from a little worm!". I don't know who would...

  10. Fankly, I'm suprised by Itninja · · Score: 3, Funny

    ...that this doesn't happen more often. I can drive through Seattle (and presumably any large city) with my laptop running a wireless network sniffer. After about 10 blocks, I could easily get into no less than 25 wireless routers. They are all configured with the default credentials. Of course, I don't. Sometimes, when it's a law firm, government agency, or some other organization with tons of [other peoples] personal information, I will even call them up and let them know about it, as a courtesy. They usually tell me to take a hike. Then I can show up at their door offering my services as a 'security consultant' (for $200/hr). 'Look here' I say. 'Look how I am easily changing the settings in your router.'. That's usually about the time they wet their $400 slacks and write me a check.

    --
    I judt got a nre Kinesis keybiartf so please excusr ant egregiou typos.
    1. Re:Fankly, I'm suprised by Anonymous Coward · · Score: 4, Insightful

      I presume you're being funny. What you're doing there is just as likely to land you in the hoosegow as a suspected terrorist or something of that nature as it is to make you money. This is not a time in U.S. history where being a Good Samaritan is even remotely a good idea.

    2. Re:Fankly, I'm suprised by canUbeleiveIT · · Score: 4, Funny

      ...that this doesn't happen more often. I can drive through Seattle (and presumably any large city) with my laptop running a wireless network sniffer. After about 10 blocks, I could easily get into no less than 25 wireless routers. They are all configured with the default credentials. Of course, I don't. Sometimes, when it's a law firm, government agency, or some other organization with tons of [other peoples] personal information, I will even call them up and let them know about it, as a courtesy. They usually tell me to take a hike. Then I can show up at their door offering my services as a 'security consultant' (for $200/hr). 'Look here' I say. 'Look how I am easily changing the settings in your router.'. That's usually about the time they wet their $400 slacks and write me a check.
      --

      "It's a simple question, doctor.
      Would you eat the moon if it was made of ribs, or not?"

      CORRECTION: Would you eat the moon if it were made of ribs, or not?

      In this case, the verb "to be" is in the subjunctive mood, which is used to indicate a situation that is hypothetical, conditional or somehow not certain.

      Now, this correction is just a courtesy. However, if you tell me to take a hike, I will show up at your door with A Writer's Reference by Diana Hacker, and you can scratch me out a check. Sorry, I don't know how much you paid for your pants.
    3. Re:Fankly, I'm suprised by canUbeleiveIT · · Score: 3, Funny

      You don't correct the grammar of a quote, douchebag.

      You do if the quote is quoted incorrectly with poor grammar, douchebag.

  11. Idiots with default passwords get pwnd, news at 11 by Anonymous Coward · · Score: 5, Insightful

    nothing to see here... move along, folks

  12. DNS cache poisoning by the_kanzure · · Score: 3, Informative
    src

    The paper shows that BIND 9 DNS queries are predictable i.e. that the source UDP port and DNS transaction ID can be effectively predicted. A predictability algorithm is described that, in optimal conditions, provides very few guesses for the "next" query (10 in the basic attack, and 1 in the advanced attack), thereby overcoming whatever protection offered by the transaction ID mechanism. This enables a much more effective DNS cache poisoning than the currently known attacks against BIND 9. The net effect is that pharming attacks are feasible against BIND 9 caching DNS servers, without the need to directly attack neither DNS servers nor clients (PCs). The results are applicable to all BIND 9 releases [1], when BIND (the named daemon) is in caching DNS server configuration.
    Langfeldt's DNS how-to
  13. Most Pooter owners too dumb to own one by Anonymous Coward · · Score: 4, Informative

    If you have a home network, there are several ways to secure it. Every router that I have ever owned have several characteristics. Look for the 'reset' key, make sure it is there and not like Asante where you have to short terminals 3 and 8 on the serial port...showin my age there folks. Make sure it is a real router and not a windows appendage. Do NOT use a PCI modem that you cannot disconnect fast. Use an external modem on a SERIAL port. Do not use a combination cable modem/router. This is foisted on many users, and as a default feature sets up remote administration from the outside. That remote admin 'feature' is 'supposed to allow customer engineers to help......' you out of all your money. Don't surf as administrator if microsoftintheheady or as root if a linux penguin. Thats just askin to get hosed. Yeah, I'm a ramblin old fart, but all these things I have picked up from experience. Definitely change the default password, 'admin' or whatever on the router to something realllly strange and long. Write that password down and put it in your wallet, your wife's ring box, or whatever. Do not even try to memorize it as you will forget it when you need it. Don't use 'DHCP' that routers and network vendors want you to do. This means that all home networks are on 192.168.1.0 or some predictable net address that all hackers try first. Use a REAL network with a real address like 192.168.205.89 or something. This forces hackers to really fail many many times in guessing your network setup. With a real network, hand out your own addresses and make them random in the third and fourth hex digits so that hackers will have to guess out each and every terminal on your net. Now add MAC security to your router so that the hacker not only has to correctly guess from a crore of non standard addresses to address it, but only those with the right computer NIC can even be qualified to guess the password! Having a switch available to shut down suspects in a hurry helps too. I could go on, but if you have followed all this rambling, print it out and do it.

    1. Re:Most Pooter owners too dumb to own one by adolf · · Score: 3, Insightful

      Good advice.

      But you forgot something: When a friend brings their PC/PSP/PS3/Wii/Xbox/iPhone/iPod over, and wants to use it with teh Intarwebs, go ahead and set it up and give them the passphrase and IP assignment, but make sure you destroy your friend before they leave.

      You can't allow any chance of your uber-obscurity leaking outside, right? Eventually, you'll eliminate all of your friends, but that has the nice benefit of eliminating the potential leaks.

      Naw, better to keep it simple. Don't run as root/admin. Set an unusual password (something other than your SO or child's name is adequate). Set a different, unusual, and lengthy, WAP passphrase. Use the strongest encryption you can with the devices on your network (AES, AES / TKIP, or just TKIP, in order of preference).

      Done.

      MAC filtering? Disabling DHCP? IP address range hide and seek?

      Bullshit. All that does is make it harder for you and the people you trust to use the network. And if I, the creepy dude in the van across the street, get to a point where any of those stupid tricks will start to matter, they won't make any difference at all. If I'm clever enough to get past WAP, then I'm clever enough to clone a MAC address while sniffing past the rest of your security-through-obscurity features.

      [And what's all that talk about serial ports? Are we still in 2008, or did we just jump back 10 years?]

    2. Re:Most Pooter owners too dumb to own one by operagost · · Score: 2

      With a real network, hand out your own addresses and make them random in the third and fourth hex digits so that hackers will have to guess out each and every terminal on your net.
      Sounds like someone doesn't understand how DHCP and subnetting work. You can change the DHCP addressing range on your router so that it gives out, say, 192.168.100.0/24. There is no need to use manual addressing unless you have untrusted people able to physically plug into your LAN. Also, IP v4 addresses can be expressed in hex, but normally decimal is used. I assume by "third and fourth hex digits" you mean the third and fourth octets. If you want to do that, you would have to use a 16 bit subnet mask. Although addressing has been classless for many years, using the range 172.16.0.0/16 would be the safest.

      Now add MAC security to your router so that the hacker not only has to correctly guess from a crore of non standard addresses to address it,
      Small children know that this can be easily circumvented with a simple network sniffer. Unfortunately, it seems that not many small children frequent Slashdot as your post has been modded up to +4. I note that you did not even mention encryption or authentication, which are two of the most common security methods (as opposed to the obscurity methods you mentioned) that one could use on a network.

      You really should reeducate yourself before you start sounding like this guy.
      --

      Gamingmuseum.com: Give your 3D accelerator a rest.
  14. Pharming??? by jez9999 · · Score: 5, Funny

    Will these terrible names, which apparently attempt to draw an analogy between a computer-related misdemeanor and some agricultural pastime, never end? I'm just waiting for some guy from F-Secure to call porn 'phucking'.

  15. Worse possibilities by Pitr · · Score: 2, Interesting

    If you change the proxy settings on routers that have them, you could wreak all kinds of havoc, as you'd have access to all traffic, not just dns requests. Or, you could update the firmware to something custom, with all kinds of sneaky badness hidden within, including blocking future clean firmware updates.

    It's a little extra work, but the companies that make these things should have unique passwords per device, or at least have logging into the admin interface wirelessly off by default. In an attempt to make things "just work" or "work right out of the box" security has suffered greatly.

    Also, if people need to read one page of detailed instructions to make their new device work, it will give them at least some tiny education about security. If they can't handle that, then they can pay someone to set it up for them. There's really no excuse for openly offering up security holes this big.

    --

    --Not to be worried, Pitr fix.
  16. Let me explain by Pasajero · · Score: 5, Informative

    I live in Mexico, and yes, the bank name is Banamex (owned by Citibank) and this is how the hack works:

    The most prominent ISP in Mexico (Telmex) uses 2wire gateway modems, most of them wireless enabled. Security is turned on by default using serial numbers so no one from outside can login "easily".

    However, there is no default security from the inside, so the gusanito.com postcard contains a malicious flash program that sends a special URL to the modem that adds a DNS entry to its local name resolution table pointing www.banamex.com to a pharming site.

    Next time you open IE or any other browser and open www.banamex.com you'll get redirected to the other site.

    This easily solved putting a user password on the modem configuration, but not all people care to do that.

    1. Re:Let me explain by nesmex · · Score: 3, Informative

      Sorry to say this but the attack overrides the modem's password, the attack from Gusanito and similar attacks (ie El Universal) probes with different common 2WIRE router addresses to get to the MDC. Fortunately it is not that elaborated... This attack was reported during late last year. This exploits a vulnerability in 2WIRE modems, as documented in US-CERT http://nvd.nist.gov/nvd.cfm?cvename=CVE-2007-4389
      Trend Micro has a more recent report on a variation of this attack http://blog.trendmicro.com/targeted-attack-in-mexico-dns-poisoning-via-modems/
      The UNAM-CERT, also has the "Gusanito" exploit documented (spanish only) at http://www.seguridad.unam.mx/doc/?ap=articulo&id=196
      The attack overrides the modem's password...

  17. Look for the "https:" by steveha · · Score: 4, Informative

    As I understand it, even with this so-called pharming technique, the bad guys still cannot correctly spoof an "https:" page... at least not without compromising the private key used to secure the SSL connection, or compromising the private key of the certificate signing authority.

    When I explain to people how to use the Web, I always tell them to look for the security indicators before doing anything involving money.

    P.S. I wouldn't be surprised if the bad guys here added Javascript code to their fake bank site, to rewrite the address bar of the web browser to show the "https:". This is why I prefer to do all my online banking with Javascript disabled; thank you, NoScript.

    steveha

    --
    lf(1): it's like ls(1) but sorts filenames by extension, tersely
  18. Last two routers I bought fixed this by patio11 · · Score: 2, Insightful

    They came with a big piece of yellow tape over the power terminal and the LAN cable ports, which said "STOP. Put the CD in first, and follow the instructions on the screen."

    The instructions on the screen were, predictably, written so that you could understand them if you were six. One of them was "Pick a username and password". Presto-changeo, no need for a factory default.

    I don't remember the makes and models of the routers, though. They're a commodity -- I went into Best Buy and, for the first time in my life, the magically appearing salesman was actually useful. "I need a wireless router." "Size of the house?" "Small." "Here." "Thanks. My, that was easy." Commodity appliances for the win.

  19. The AC has it right! by SMS_Design · · Score: 2, Insightful

    Because "hackers" can't run a packet sniffer and have all of that info in 30 seconds.

    Security by obscurity. Great policy.