Cybercriminals Building New, Stealthier Networks

ancientribe writes "Cybercriminals are adopting a new method of hiding and sustaining their malicious Websites and botnet infrastructures so they'll be harder to detect, called "fast-flux," according to an article in Dark Reading. Criminal organizations behind two infamous malware families — Warezov/Stration and Storm — in the past few months have separately moved their infrastructures to so-called fast-flux service networks. The article says bad guys like fast-flux not only because it keeps them up and running, but also because it's more efficient than traditional methods of infecting victims' machines." I'm not exactly sure why this is new/different than the more well known open relay proxy networks.

Comments

Block TCP Port 80

[quanticle]

What can be done about fast flux? ISPs and users should probe suspicious nodes and use intrusion detection systems; block TCP port 80 and UDP port 53; block access to mother ship and other controller machines when detected; "blackhole" DNS and BGP route-injection; and monitor DNS, the report says.

The bit about blocking TCP port 80 is troubling. I run a small web-site for learning purposes and to share info with family and friends. I don't especially like the possibility of having to ask or pay extra to have port 80 opened on my end.

Re:Block TCP Port 80

[veganboyjosh]

Mr. Potatahead! Mr. PotataHEAD! Getting around port blocks is not secret!

Re:Block TCP Port 80

[Anonymous Coward]

With power comes responsibility. If you want unfettered internet access, it's your responsibility to make sure that your participation in this network doesn't cause problems for others. Since most residential internet users have neither the ability nor the intention to shoulder that responsibility, their upstream provider has to find ways to protect other internet users from his customers, because if he doesn't, he will ultimately have to pay for the damage that they do (higher traffic costs, less favorable peering agreements, blacklisting, etc.)

The net has grown very fast and so far we've shirked the responsibility issue: Customer's complain about spam and when the spammer's provider says it's not their responsibility, they're called a safe-haven for spammers. On the other hand, when customers get cut off because their computers are scanning and infecting other machines, they complain that it's not their fault and how are they supposed to keep their system clean without a full time admin and it's none of the ISPs business as long as the internet access bills are paid.

Re:Block TCP Port 80

[utopianfiat]

This is what Slashdot has become.
Two years ago there would have been a frosty piss and a two-page discussion on how this douchebag OP was wrong to use the word "cybercriminals" (or cyberfoo for that matter), and how his article reads like a page out of the script to this flaming piece of shit. Where did we go? Since when did Slashdot become Eternal September?
That's right point-bearing masses, mod me flamebait because nobody else has the balls to stand up to this kind of terrible quality news. FFS look at the damn article! It says nothing! It literally states something that was true ten years ago when the botnet was invented! News for NERDS? more like News for NEWBS.
Christ alfuckingmighty.

" why is this new/different"

[tomhudson]

"I'm not exactly sure why this is new/different than the more well known open relay proxy networks."

... which just goes to show that even spammers can fall victim to their own marketing:

Tired of your botnets getting killed off? Use fast-flux. See a 30% increase in only 2 days. She'll love you for it!.

Know Your Enemy paper on Fast Flux just out

[Anonymous Coward]

Has a lot more detail: http://www.honeynet.org/papers/ff/fast-flux.html

Re:What's special about port 80?

[orclevegam]

The blocking of port 80 they suggest really isn't about stopping the fast flux network, but it's an attempt to make it harder (marginally) to use the systems on that network for phishing attacks. As I understand it one of the uses these networks are being put to is to duplicate a phishing site on a couple hundred zombie systems, then rotate a single phishing URL through all of them making it harder to bring down the phishing site because you'd have to take down every one of the zombies, or find some way of nuking the DNS entry (which apparently the registrars are hesitant to do, even though some recent events seem to show that they'll do it quite happily if a big enough company or corporation asks them to). Personally I think blocking port 80 is a dumb idea and barely constitutes a speed bump for the kinds of people that run these things, but hey, that's never stopped a company from adopting a stupid idea, or marginal positive value and substantial negative (to the customer, if it hurts their bottom line forget it).

Re:What's special about port 80?

[Control Group]

*shrug*

Randomly select a different port each time you connect to the zombie. If you're really worried about users running netstat to check their open ports (and I suspect that zombied machines are more often owned by people who don't even know the CLI exists, much less who generally run network diagnostic tools via the CLI than not - and by a wide margin), then have it only open the port for ten minutes every hour. Windows, by default, updates its clock to NIST weekly, so you can be reasonably sure that your zombies are synced enough for that to work. Round-robin assign the ten minute window to the zombies (xx:00 - xx:09, xx:01 - xx:10, xx:02 - xx:11, etc). During that window, you use the zombie to host content, and you can push a listen port update. At any given time, most of your zombies are running on the same port (they have to be, or your victims can't connect to your content), but blocking that port will only be effective for however long you determine. How fast can ISPs identify a rogue port and block it?

If my experience with spam is any indication, the linked sites go down almost as fast as the spam comes in, but that's (apparently) not a problem for the spammers. So you rotate ports every two, three days.

And this is just the scheme I've come up with off the top of my head in less than a minute.

Come to think of it, you're already executing arbitrary code on the zombied machine. Have them determine when they can listen on their assigned port, with a minimum frequency and duration set, with a bias towards times the user isn't at the console. When the window opens, step one is to notify the mother ship that this machine is active.

There are probably holes in this scheme, but I don't see the problem as being intractable. I do see any effort to just block port 80 as being naive (at best). I don't think ISPs can respond fast enough to block a new port every couple days, but perhaps I'm wrong about that.

Fast-flux networks aren't proxies

[jbsoles]

As the subject implies, fast-flux networks are not proxies. They HAVE proxies. The basic difference is that a proxy redirects incoming and outgoing traffic through a server or router some where else, thus "spoofing" your IP address. Fast-flux networks certainly use proxies, but there's one big difference; fast-flux networks allow you to host content this way. To host your own website (short of technical mastery) you used to need a static IP address that runs directly to one or more servers, making it very easy to catch you if you use a domain name for illegal purposes and even easier to shut you down. Fast-flux networks allow you to use many IP addresses to host content from one central server or set of servers. The IP's on the front end are disposable and more can be generated quickly. It also provides the web site administrator a proxy level to protect his identity while hosting just like the one Tor proxy provides me while surfing. In other words, the difference between fast-flux networks and proxies is that fast-flux networks can be used to host from one computer to many different IP addresses, in part by using proxies. A proxy just doesn't let you do that. Thanks for reading a rather long post. I'm a student and a paper on fast-flux networks just happened to be distributed where I do research for the summer:)