Is it the end of October already? As has been true for centuries, there is a tradition for children to wear costumes and disguise themselves while going door to door with a simple question: “Trick or treat?” While I am not sure there is a coincidence, but having National Cyber Security Awareness Month (NCSAM) end on a day characterized by pranks, false identifications and the like seems appropriate. And what scary stories we had to tell!
Stop-think-connect is not only for kids. Everyone, including nerds like me and network and security professionals, should pay more attention before connecting any device to the Internet. Routers (wireless and wired), industrial control systems, video surveillance cameras, fire alarm systems, traffic cameras, home and building automation systems, and many other devices are being connected to the Internet every single day, wide open. If you don’t believe me do a quick search on SHODAN.
In the past couple of years, cloud-based solutions have gone from the status of a brave new technology to a mainstream vehicle for delivering storage, application, infrastructure and other services. From a security point of view, consuming cloud-based services usually involves delegating security for the service to the service provider. This does not need to be as scary as it sounds – as long as you approach the service engagement with your eyes open, and arm yourself with pertinent requirements for the service provider to provide appropriate controls to protect your organization.
Employees of every organization use a variety of computing devices such as desktops, servers, laptops, security appliances, and mobile devices to increase productivity in this ever-changing world of Information Technology. The confidentiality, integrity, and availability (CIA) of information has become essential to success and often a competitive advantage. A comprehensive patch management process should be a major component to protecting CIA on computing devices and the data they store or transmit. Patch management is not always a simple task, as organizations may have a variety of platforms and configurations, along with other challenges that make patching these components very difficult. However, there are recommendations and best practices to minimize the complexity of this much-needed task.
The Great Correlate Debate
SIEMs have been pitched in the past as “correlation engines” and their special algorithms can take in volumes of logs and filter everything down to just the good stuff. In its most basic form, correlation is a mathematical, statistical, or logical relationship between a set of different events. Correlation is incredibly important, and is a very powerful method for confirming details of a security incident. Correlation helps shake out circumstantial evidence, which is completely fair to use in the incident response game. Noticing one alarm from one host can certainly be compelling evidence, but in many cases it’s not sufficient. Let’s say my web proxy logs indicate a host on the network was a possible victim of a drive-by download attack. The SIEM could notify the analysts team that this issue occurred, but what do we really know at this point? That some host may have downloaded a complete file from a bad host -- that’s it. We don’t know if it has been unpacked, executed, etc. and have no idea if the threat is still relevant. If the antivirus deleted or otherwise quarantined the file, do we still have anything to worry about? If the proxy blocked the file from downloading, what does that mean for this incident?
This is the problem that correlation can solve. If after the malware file downloaded we see port scanning behavior, large outbound netflow to unusual servers, repeated connections to PHP scripts hosted in sketchy places, or other suspicious activity from the same host, we can create an incident for the host based on our additional details. The order is important as well. Since most attacks follow the same pattern (bait, redirect, exploit, additional malware delivery, check-in), we tie these steps together with security alarms and timestamps. If we see the events happening in the proper order we can be assured an incident has occurred.