When investigating a crime in the physical world, successful detectives are able to put together individual pieces of evidence to unveil a criminal’s pattern of behavior. A single footprint is interesting; it gives you the size of the bad guy’s foot and what type of shoes he wore. The bad guy can change his shoes between crimes, of course, but he probably won’t come up with a new technique for breaking into individual houses. An understanding of a criminal’s behavior – his patterns, if you will -- can give investigators a level of insight that will help them catch that criminal the next time he attempts to do something bad, new shoes or not.
This way of approaching the problem can also tie together multiple incidents that were previously thought unrelated, perhaps because the weapons or descriptions of the individuals performing the crimes weren’t exactly the same.
In the cybersecurity world, we call these behavior patterns “patterns of attack,” and they are revolutionizing the way breach detection and incident response is being conducted around the world.
You’ve no doubt heard the term “indicators of compromise.” IOCs are -- in the way the security community typically thinks about them -- atomic pieces of information or singular attributes. Examples of IOCs are IP addresses, domain names, URLs, file hashes, and similar metadata around tools or actions that occurred during an attack. But context matters -- a lot -- and it’s hard to know context when all you have is an IP address or file hash.
Context Is Critical
Solving cybercrimes (or any crime, really) requires context, and to get context you have to look at relationships. Relationships between IOCs and other events are often patterns of behavior, and that’s why the shift beyond IOCs is occurring.
When your company’s intellectual property and reputation are on the line, the CEO wants to hear something a lot more confident than: “We have an indication of how we might have been attacked.” Instead, she wants to hear: “We have a precise record of what this attacker tried to do. We know exactly what they actually did. We’ve closed the gap. They cannot attack us this same way again.”
Patterns of attack provide investigators with the precise sequence of events as a cybercrime unfolds. There is clear cause-and-effect insight into where an attacker gained access, what he tried to do, how he attempted exfiltration, and ultimately what the exact root cause of the attack was. If an investigator does not understand the root cause of the attack, he’s provided no additional insight into how an organization can be better protected in the future.
Patterns reveal exponentially more relevant information about attempted malfeasance than singular indicators of an attack ever could. Context, relationships, and the sequence of events all matter. If you’re just looking for one item in the sequence of events, that’s when issues such as too many tips -- or in the cyberworld, false positives -- start becoming a bigger issue than the malicious behavior itself. After all, if you cannot respond to a tip or an alert, it’s just noise.