The public cloud holds tremendous possibilities for goodness in lowering computing costs and increasing flexibility, but the dark side of the world is always ready to take advantage of cloud delivery models like Platform-as-a-Service (PaaS). Arbor Networks recently spotted a Google AppEngine Platform-as-a-Service application being used for Command and Control (CnC) for a botnet (here is a news article). Google promptly took down the application, but the event raises some interesting issues.
In the malware realm, this is nothing new and has been referred to previously as “Malware as a Service”. Just as legitimate companies move to the cloud for the above-mentioned benefits, cybercriminals move some of their malware onto “shared infrastructure” sites to make them harder to mitigate, block, or get taken down. What is somewhat new is the increase of hosted malware in Google applications (e.g. Google Reader, Blogger, etc.).
What caught my attention was that the bad guys quickly learned to leverage the PaaS cloud infrastructure for malware CnC. It does not take a fertile imagination to see bad guys going from using PaaS to manage their malware to applying knowledge to go after IaaS applications. The public cloud (SaaS/PaaS/IaaS) has a compelling value proposition in terms of cost, but “out of the box” IaaS only provides basic security (perimeter firewall, load balancing, etc) and applications moving into the cloud will need higher levels of security provided at the host by layers such as Trend Micro Deep Security 7.0. Such countermeasures would mitigate the possibility that a bad guy might attack an IaaS instance or take it over for use as a botnet hub.
If someone with malicious intent buys up the IaaS instances, it’s seems to me that the Service Provider should detect and stop that as a violation of the Service Provider Service Level Agreement (SLA). But how does a service provider assess how their IaaS/PaaS is being used without compromising the privacy of the application? If they don’t watch the usage, perhaps they have to validate the customer? And what if the service is bought with stolen personally identifiable information (PII) and credit card numbers?
The malware threat is as old, but the cloud poses some new questions.