Malware on Hijacked Subdomains, a New Trend? 24
The Unmask Parasites blog discusses a technique attackers are using more and more often recently: modifying a compromised site's DNS settings to redirect various subdomains to different IPs that serve up malware, often leaving site administrators none the wiser. Quoting:
"It is clear that hackers have figured out that subdomains of legitimate websites are an almost infinite source of free domain names for their attack sites. With access to DNS settings, they can create arbitrary subdomains that point to their own servers. Such subdomains can hardly be noticed by domain owners who rarely check their DNS records after the initial domain configuration. And they cost nothing to hackers. I wonder if using hijacked subdomains of legitimate websites is a new trend in malware distribution or just a temporarily solution that won't be widely adopted by cybercriminals in the long run (like dynamic DNS domains last September)."
Also done with 404 Error Documents (Score:5, Informative)
This is also done with 404 Error pages. They change it to redirect to their spam, and then point people at what looks like a legitimate URL. Then they get redirected to the spam and are none the wiser. www.slashdot.org/thisdoesntexist could redirect anywhere.
Re:Also done with 404 Error Documents (Score:4, Informative)
Agreed 404, 301, 302. Anything that you can drop a .htaccess file into an account.
Ideally, web servers (not just DNS) have a lot of holes, allowing NS access to the user isn't the problem like the TFA implies. Because most automation software doesn't allow for too much sub domain specific flexibility, most times you still need to be in root to redirect at a dns level.
The exception is say parking (godaddy etc) or zoneedit but usually once its hosted it's pretty much in the hands of the admin to delegate externally.
Re:Also done with 404 Error Documents (Score:4, Informative)
Re: (Score:3, Interesting)
So can these hacks be used to get around "NoScript"? I currently have it set to:
- Temporarily allow top-level sites by defualt
--- Base 2nd level Domains (noscript.net)
Re: (Score:2)
In general, any security tool configured to trust a subdomain of a trusted domain would be vulnerable to this attack.
See also "Trusted Sites" in IE.
Re: (Score:1)
Wildcard SSL (Score:3, Interesting)
Since a lot of hosting automation software (cPanel) sets up an a name for @ giving the power singularly to apache also lends it self to have the ability to mask it as being secure.
It isnt a nameserver its moreover a webserver one.
Administrator negligence? (Score:3, Insightful)
"who rarely check their DNS records"
And thereinlies both the problem and the solution.
Re:Administrator negligence? (Score:4, Insightful)
I see the best way is to notify admin upon a dns change, any external sites added get sent via email.
(sounds like a job for the guys at http://www.configserver.com/ [configserver.com])
unravel the illicit infrastructure (Score:4, Insightful)
Yes, checking the DNS records will help identify the sites that have been modified, however it will also identify the hackers servers IP numbers. With that thread, you can start to unravel the illicit infrastructure, and counteract it.
Re: (Score:2, Interesting)
That explains idle.slashdot.org (Score:5, Funny)
That explains idle.slashdot.org :-)
A wierd habit of mine . . . (Score:2)
There are a number of well known DNS exploits, especially with DNSSEC (http://www.dnssec.net) being a late comer to the Internet and not widely implemented beyond top level d
Re: (Score:2)
Google now has a public DNS server at 8.8.8.8, which is also very easy to remember. (and very fast)
As a malware defense professional.. (Score:5, Informative)
Re: (Score:2)
As a malware defense professional..
Man, that's got to make you feel as good as working for a large bank makes me feel ;)
Re: (Score:1)
Misread headlines (Score:2, Funny)
"Malware on Hijacked Submarines, a New Trend?"
Talk about a double-take! Would have made for an interesting story, though :)
A permanent trend? (Score:2)
> I wonder if using hijacked subdomains of legitimate websites is a new trend in malware distribution or just a temporarily solution that won’t be widely adopted by cybercriminals in the long run (like dynamic DNS domains last September).
Well, if my co-workers' research with URL-shortener links is any indication, you can certainly train people in a Pavlovian manner to avoid following links to unknown content.