Zombie PCs are for crimelord chumps: Fear clusters, says infosec ace

'Dumb' distributed computing vs 'smart' distributed computing

"We're able to attack far more targets that we would otherwise be able to, not least because we're able to do so quickly enough to 'outrun' any countermeasures," Caceres told El Reg. "An attacker could find and exploit vulnerabilities against a massive bed of targets in a short period of time, and these attacks be extremely effective," he added.

Distributed computing is more flexible as an attack platform than conventional botnets. "Since we're using an advanced distributed platform (Hadoop), the level of coordination between assets is much greater than with a simple botnet," Caceres told El Reg.

"For example Hadoop can be used to ensure that your assets are using all of their available resources, and ensures that your distributed job goes off without a hitch. Botnets by nature are usually 'dumb' distributed computing - this is "smart" distributed computing."

Building a cluster of machines to act as a platform for attacks wouldn't be expensive, according to Caceres.

"Very little would have to be invested," he explained. "I built my first effective Hadoop cluster for free using donated hardware, it got up to about 10 machines before I moved over to the cloud, but was very effective."

The researcher added: "The cloud can be extremely cheap or a bit expensive depending on how you do it. Amazon has a service called EMR which is essentially a rent-a-Hadoop-cluster deal where you only get charged for as long as your Hadoop job runs.

"This can be very cheap, since you can spin up a big cluster and have it automatically shut down as soon as you're done. My demo for PunkCRACK was using this service, and it cost me about 20 bucks to rent a cluster of 20 massive computers (32 processor cores each) for a couple of hours to do my bidding. Having a persistent cluster can cost you a few hundred dollars a month depending on the size of the servers."

Not just for baddies

As we all know, Big Data technology has many benevolent uses, not least in the infosec world. For example, Caceres' PunkSPIDER, a distributed vulnerability scanner. "PunkSPIDER provides information back to the public so that they can make educated choices on their site visiting activities," Caceres explained. "It could also allow large organisations with lots of targets to try these attacks against themselves and see how they fare. One thing I mentioned in my talk is, imagine penetration-testing an entire country."

During a second talk at DefCon Caceres outlined research about a 3D distributed vulnerability visualisation engine. "It uses many of the same principles (distributed vulnerability finding) as the attack-focused talk, but applies them to defence and understanding of web vulnerabilities," he explained.

Defences against distributed computing attacks might involve using similar cloud-based systems to search for vulnerabilities before they get exploited, according to Caceres.

"The defence is actually quite simple - fix your most obvious vulnerabilities before you move on to mitigating advanced threats," he said. "The techniques outlined allow an attacker to act like an army of attackers using automated scanning and exploitation attacks - they will very effectively find and attack the low-hanging fruit.

"The problem, in my opinion, with most organisations is that they're being sold on buzzwords like APT, advanced malware, etc, and are buying technologies to mitigate these threats. Before moving on to protecting against these complex threats, make sure you don't have an incredibly obvious SQL injection vulnerability in your public-facing site, or extremely outdated patches.

"Unless organisations learn to crawl before they walk, they're not going to get anywhere in general, and these types of attacks (along with many other attacks) will continue to be extremely effective." ®