Stop chasing ghosts and build a threat hunting strategy
- By Kevin Keeney
- Jan 22, 2019
As a federal IT community, we have to admit that adversaries are often already inside our networks and infrastructures. In today’s cybersecurity world, it’s foolish to assume that with all the right tools in place agencies can keep the “bad guys” out. The real question is, what do we do about them once they're inside?
Federal agencies are dealing with well-funded threats from nation-states that are operating in novel ways, with new technologies that defensive cyber tools are struggling to match. These adversaries are far more difficult to anticipate and predict, limiting our ability to counter threats. It’s a little like chasing ghosts -- we’re never quite sure what we’re up against -- and the solution requires human intelligence.
Enter threat hunting.
Cybersecurity historically has been reactive. Security tools were designed around “known knowns.” We generally knew how attackers would operate -- often rogue actors with limited resources who followed a standard hacker's playbook -- and we set up defenses to stop them.
Today, that’s all changed. Threat hunting is a security strategy centered on proactively searching for threats, based on intelligence about the organization and its adversaries. Every hunt starts with an anomaly, followed by a hypothesis based on human intelligence. Then it’s about asking the right questions of the data to validate or invalidate the theory.
Searching, not alerting
Threat hunting is the antithesis of alerting. While alerts are extremely useful, alert fatigue is real. Seeing the same alert day after day, even if it is a legitimate event, builds apathy and frustration across security teams. Threat hunting requires a mindset shift from that alert culture. It acknowledges that threats exist within the environment and they can be found by proactively hunting for them.
But in order to hunt, agencies must be able to search through IT logs, firewalls, databases, intranets and clouds. The search increases in complexity as it sifts through data in a variety of different formats, both structured and unstructured, across all of these workloads. Today’s search tools have the power to unlock these different data types so they can be indexed, analyzed and displayed in a way that delivers the insights federal IT leaders need to start their hunt.
Using knowledge about their agency's vulnerabilities, as well as understanding about likely adversaries and what they may want, IT and security teams can query data from every corner of their infrastructure, test hypotheses and identify abnormal activity. And now they can do it in seconds.
Speed is everything
Threat hunting is a numbers game. Not every hypothesis is going to unearth a threat. In fact, most aren’t. That’s why agencies need tools fast enough to test hypotheses, fail quickly and then move on to the next hunt. This need for speed is tied to the modernization of systems.
Federal CIO Suzanne Kent recently spoke to the need to analyze data fast enough for it to be usable. “If one of us tried to process a terabyte of data, we would have to watch the equivalent of 400 90-minute videos,” she said. "Using technology, and with the right discipline around data, we can process that in seconds. But it has to be structured, and we have to understand it.”
While enterprise search tools date back to the days of the mainframe, agency search needs are much more complex now. Today’s distributed systems need high-volume, deep-dive searches that can happen in real time and continually update indexes as new data is added. Searches must yield insights fast enough to empower agencies to make critical mission decisions. If it takes weeks to get to the right answer, it’s probably too late.
Don’t hunt in siloes
Some hunting is already taking place at federal agencies, but it’s often happening in siloes. IT and security leaders are only capable of testing hypotheses within certain systems across firewalls, detection platforms, endpoint agents and other services. For example, there are point solutions that are great at evaluating endpoint data only -- and while this is better than having no threat hunting tool at all, it doesn’t empower agencies to see the big picture. Real threat hunting requires tools that look across the entire agency to find anomalies that cross boundaries and siloes.
Additionally, limiting threat hunts to individual systems could actually open up new attack vectors. If bad actors are monitoring an agency's investigation tactics, they can adjust strategies on the fly and double down on attacking areas that haven't been prioritized.
It takes a village
For too long, organizations have carried their own unique cyber burden. They didn’t want anyone to know about the threats they were constantly facing, and they were reluctant to share their findings around weaknesses for fear of ridicule or retribution. But the reality is that we’re all in this together -- both the public and private sectors -- and we are often battling common enemies.
Today, the security community has formed a number of Ghostbusters-type organizations designed to share best practices, alert each other to new threats and collaborate on solutions (even if it means crossing the streams). Making sure these communities include experts from government, the contracting community and security vendors is critical to build a full picture of cyber needs and strategies.
Ironically, while humans are often (accurately) cited as the weak link in an organization’s security, they are also the critical link to building and executing a successful threat hunting strategy. It may feel like chasing ghosts as bad actors slip in and out of our systems, but cybersecurity is a very a human problem, and it requires human solutions.
This is the fight of our time. Combining human intelligence with the best automated detection and search tools is our best chance for staying one step ahead.
Kevin Keeney is a cyber security advocate with Elastic.