There is quite a bit of talk online right now about a new bot-net that is supposedly quite a bit larger than Storm. This new bot-net, called Kraken, was discovered and initially revealed by another security team. Various folks are pointing at it as another evolutionary step in the growth of the bot-net threat and as a major new development in the area of cyber-crime.
Bot-nets, it seems, are today’s Internet worms. Their power, capability to produce FUD and impact make them on par with the Slammer, Code Red and Nimda worms of the past as significant threat evolutions. However, just like the worms of yesterday, there are some pretty common – albeit sometimes tough – things you can do to help minimize your risk of exposure.
First, segregate your network. Create enclaves that separate and manage access to servers that hold critical or sensitive data. Basically, segregate any and all user systems into untrusted areas and manage them as if they were untrusted systems (they are!!!)
Next, deploy egress controls as tightly as possible for all user -> Internet activity. Apply egress controls as tightly as possible to all enclaves.
Now, ensure that you have proper preventative and monitoring controls on all of the enclaves. Check for unneeded services, missing patches (OS and applications), bad configurations and known security issues. Mitigate or repair as many as possible. Monitor everything at the egress point for forensics and help with finding infected hosts. Deploy HoneyPoint sensors in user community and all enclaves.
Harden the user systems to the largest extent possible. AV, personal firewalls, patches, consider hardening or changing browsers. No matter what, consider user systems as untrusted hosts!
Educate your users about threats, their responsibilities and security mechanisms for their systems when outside the corporate network.
Monitor, manage and handle incidents quickly and with public consequences. If you find an infected machine and can trace it back to porn downloads on a company machine, fire the person and make a public example of the fact that actions against security policy (you have one of those, right?) have consequences…
Doing these basics will increase your overall security and greatly reduce your risk from bot-nets (and other threats). Is it easy? No. Is it expensive? It can be, depending on your size, complexity and technology level. Is it worth doing? Yes. It reduces risk and is much more interesting than ignoring the problem and/or continually working reactively to various incidents and compromises.