I'd like to briefly point you to two must-read articles, if you haven't seen them already. First, the Honeynet Project published Fast-Flux Service Networks. Basically, intruders have introduced availability and load balancing features into their bot networks by quickly changing the IP addresses of redirectors pointing to back end servers (a technique called "single flux"). They may also rapidly change the IP addresses of the authoritative domain name servers (called "double flux") to further complicate identifying and shutting down bot nets. I'd like to hear how many of you predicted this would happen before the technique was reported by the Honeynet Project this month. Of those that say "I knew," did you know about it a year ago, when it was first detected by the Honeynet Project? And if you have known about it or predicted it, what did you or your security team do to detect and/or mitigate the attack?
My point is the vast majority of enterprises have not known about this, and they have no way to know if they've been affected. However, if you've been implementing Network Security Monitoring for any decent period of time, you have a rich data source to mine for indications of this activity. Now that you know what to look for, you can see if you're affected. The power of NSM is keeping track of what's happening on your network so that you can perform investigations once you know where to look.
A news story on fast flux is Attackers Hide in Fast Flux.
Second, Prevx posted a blog entry titled Ransomware... Holding Corporate America Ransom! that outlines another extortion attempt whereby an intruder will encrypt a victim's data if $300 isn't paid. The fact that money is explicitly involved means law enforcement should be able to "follow the money" to find the attacker, but still consider this: what would your organization do if executives and/or users received such notifications? Worse, what if your data was simply deleted, encrypted, or subtly altered, nevermind outright stolen? In other words, you aren't extorted -- you're simply assaulted.
While ransomware is not a new phenomenon, many people do not stop to think of the damage that can be done by not maintaining control of one's assets. Some of you will say "oh, we'll restore from backups." What do you do if you have dozens, hundreds, thousands of users affected? My point is we have to treat compromise of the endpoint as a serious matter, not something that has little or no consequence.
A news story on ransomware is Your Money or Your Documents.
On a related note, check out New Proxy Bot Method and Sigs. Basically the Bleeding Threats team has detected malware that uses compromised hosts as a proxy back into the corporate network. David Bianco reminded me that the Metasploit Meterpreter's portfw function provides the same capability. In other words, once a host is compromised via a client-side attack and it reports back to its command server, the command server can use the new victim as a stepping stone to attack any other reachable part of the enterprise.
Knowing how all three of these attacks operates allows us to build attack profiles so we can better resist, detect, and respond to them when they occur.
Update: Check out Passive Monitoring of DNS Anomalies at CAIDA.