Taming the Beast: Preventing/Detecting Insider Threat

The insider threat is continually occurring, even if companies do not realize it. What makes the insider threat such a significant problem is that it cannot be prevented like an external attack. If someone is running a buffer overflow attack against your system, you can patch the system and prevent the attack from occurring. If someone is connecting to your Web server and exploiting port 80, you can close down port 80 or block it at the firewall. The problem with the insider threat is that there is no patch and it is impossible to just shut it down. In order to shut down the insider threat, an organization must remove all insiders (employees). For obvious reasons this is not a practical solution and would undoubtedly put any organization out of business.

The problem with the insider threat is that it is impossible to 100 percent prevent it from happening. While there are many steps organizations can take to minimize the insider threat, it is impossible to completely eliminate it. External attacks, such as exploiting vulnerabilities, can be 100 percent prevented by installing security patches. Unfortunately the insider threat cannot be 100 percent prevented because employees must have access to company resources in order to perform their job duties. If all company resources were to be removed, well, it is easy to see that the company would quickly fail. Organizations need to take all possible precautions to stop the insider threat, but they must also realize that prevention alone is not enough.

A key theme when dealing with the insider threat is, “Prevention is ideal, but detection is a must.” When dealing with the insider threat, prevention will take you only so far. When prevention fails, it is critical that the problem be detected in a timely manner. Think of it like this: Ideally you would like to stop a fire from occurring in your house; however, if a fire does occur you want to make sure you can detect it in a timely manner. That is why smoke detectors are installed.

This raises a critical issue with detection. Detection does absolutely nothing if no one responds to the problem being detected. A smoke detector will detect a fire, but if no one responds to the fire, it will continue to burn. A detective measure needs some type of intervention. Ideally we want to prevent problems, but if prevention is not possible, detective measures need to be deployed in such a way that someone will respond to the problem in a timely manner. If an organization detects a problem and no one responds to it, then what was the purpose of detecting the problem in the first place?

Dr. Eric Cole, Ph.D., is a security expert with more than 15 years of hands-on experience. Cole has experience in information technology with a focus on perimeter defense, secure network design, vulnerability discovery, penetration testing, and intrusion detection systems. He is the author of several books, including Hackers Beware, Hiding in Plain Site, Network Security Bible, and Insider Threat. He is the inventor of more than 20 patents, and is a researcher, writer, and speaker. Cole is a member of the Commission on Cyber Security for the 44th President and several executive advisory boards, and is CTO of the Americas for McAfee. Cole is involved with the SANS Technology Institute (STI) and SANS working with students, teaching, and maintaining and developing courseware. He is a SANS fellow, instructor, and course author.