Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Endpoint Security

Going Deeper on Behavioral Detection

As attackers have become better at evading traditional signatures and malware sandboxes, security teams are increasingly turning to behavior-based detection models to find the signs of an active cyber attack. This behavioral approach to finding threats comes with a lot of advantages.

As attackers have become better at evading traditional signatures and malware sandboxes, security teams are increasingly turning to behavior-based detection models to find the signs of an active cyber attack. This behavioral approach to finding threats comes with a lot of advantages. Behavioral detection models can focus in on what the attacker actually does, instead of relying on a set of signatures or known indicators of compromise that often lag behind attackers. 

For example, while the perimeter IPS may have missed a drive-by-download, behavioral analytics could recognize that the victim end-user is starting to behave very strangely – perhaps trying to access abnormal resources or download an abnormal amount of files. This is actually exactly the sort of thing that the original intrusion detection systems were designed to do back in the 1980s.

However, we’d also be remiss if we didn’t remember why behavioral approaches to IDS fell out of favor in the first place. More often than not, analytics based on user behavior will identify anomalies as opposed to threats. Joe in accounting is downloading more data than he normally does, but is that a sign of an attack, or does Joe simply need to access a lot of data for a report he is working on? 

This sort of user behavior modeling can let us know when something doesn’t seem normal, but it is often inconclusive and requires an analyst to go investigate. The shortage of time and talent in real-world security teams typically means that these sorts of anomaly-based detections become noise that ends up being ignored.

Refocusing on Attacker Behaviors

While detections based on end-user behaviors are extremely important, we need to complement them with better detections for attacker behaviors as well. By attacker behavior, I mean a return to detecting the tools and techniques of an attack. Ultimately, if we can’t distinguish what is good from bad, then anomalies will remain ambiguous noise that creates more work for overloaded analysts. Obviously relying on manual human analysis just doesn’t scale in most environments.

If you know what to look for, malicious tools and techniques have distinguishing behaviors that can be identified. For example, attackers will often rely on custom tunneling tools to control their attack. These tools are customized to bypass signatures and intelligence feeds. However, these tools also share a characteristic set of fundamental behaviors. The initial connection comes from an infected end-user device within the network, so that the traffic blends in with normal Internet traffic. With the connection established, the remote attacker can take over real-time control of the internal host to drive the attack. Behaviorally, this action stands out. The behavior of the connection is no longer that of an internal human talking to an external server. In fact the reverse is true – you have an external human controlling one of your network devices as a drone. This sort of behavior isn’t anomalous based on past behavior. It is a significant risk based on how it is actually behaving. 

This is just one example, but the concept applies to all types of threats and can be invaluable streamlining the daily management of security events. A host may begin behaving anomalously by visiting unusual domains. However, being able to recognize the behavior of Bitcoin mining on the host lets an analyst know specifically what the issue is. This insight alone could help the analyst prioritize the event, and avoid time-consuming manual analysis. 

Advertisement. Scroll to continue reading.

The point here isn’t to say one approach is better than another, but rather to show that there is an important middle step between traditional signatures and anomaly detection. Behavior-based detection models can see the things that simple signatures miss, and can provide more clarity than only looking at anomalies. These are complimentary approaches that ideally need to work with one another in context. This gives us multiple perspectives to detect threats, and ultimately that is what we will keep us safe even as threats continue to evolve. 

Written By

Click to comment

Trending

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Gain valuable insights from industry professionals who will help guide you through the intricacies of industrial cybersecurity.

Register

Join us for an in depth exploration of the critical nature of software and vendor supply chain security issues with a focus on understanding how attacks against identity infrastructure come with major cascading effects.

Register

Expert Insights

Related Content

Cybercrime

The changing nature of what we still generally call ransomware will continue through 2023, driven by three primary conditions.

Cybercrime

A recently disclosed vBulletin vulnerability, which had a zero-day status for roughly two days last week, was exploited in a hacker attack targeting the...

Malware & Threats

The NSA and FBI warn that a Chinese state-sponsored APT called BlackTech is hacking into network edge devices and using firmware implants to silently...

Endpoint Security

Today, on January 10, 2023, Windows 7 Extended Security Updates (ESU) and Windows 8.1 have reached their end of support dates.

Application Security

Virtualization technology giant VMware on Tuesday shipped urgent updates to fix a trio of security problems in multiple software products, including a virtual machine...

Malware & Threats

Unpatched and unprotected VMware ESXi servers worldwide have been targeted in a ransomware attack exploiting a vulnerability patched in 2021.

Cybercrime

No one combatting cybercrime knows everything, but everyone in the battle has some intelligence to contribute to the larger knowledge base.

Cybercrime

The recent ransomware attack targeting Rackspace was conducted by a cybercrime group named Play using a new exploitation method, the cloud company revealed this...