Cybersecurity 101: What You Need To Know About False Positives and False Negatives

An Overview of False Positives and False Negatives

Understanding the differences between false positives and false negatives, and how they’re related to cybersecurity is important for anyone working in information security. Why? Investigating false positives is a waste of time as well as resources and distracts your team from focusing on real cyber incidents (alerts) originating from your SIEM.

On the flip side, missing false negatives (uncaught threats) increases your cyber risk, reduces your ability to respond to those attackers, and in the event of a data breach, could lead to the end of your business.

What Are False Positives?

False positives are mislabeled security alerts, indicating there is a threat when in actuality, there isn’t. These false/non-malicious alerts (SIEM events) increase noise for already over-worked security teams and can include software bugs, poorly written software, or unrecognized network traffic.

By default, most security teams are conditioned to ignore false positives. Unfortunately, this practice of ignoring security alerts — no matter how trivial they may seem — can create alert fatigue and cause your team to miss actual, important alerts related to real/malicious cyber threats (as was the case with the Target data breach).

These false alarms account for roughly 40% of the alerts cybersecurity teams receive on a daily basis and at large organizations can be overwhelming and a huge waste of time.

What Are False Negatives?

False negatives are uncaught cyber threats — overlooked by security tooling because they’re dormant, highly sophisticated (i.e. file-less or capable of lateral movement) or the security infrastructure in place lacks the technological ability to detect these attacks.

These advanced/hidden cyber threats are capable of evading prevention technologies, like next-gen firewalls, antivirus software, and endpoint detection and response (EDR) platforms trained to look for “known” attacks and malware.

No cybersecurity or data breach prevention technology can block 100% of the threats they encounter. False positives are among the 1% (roughly) of malicious malware and cyber threats most methods of prevention are prone to miss.

Strengthening Your Cybersecurity Posture

The existence of both false positives and false negatives begs the question: Does your cybersecurity strategy include proactive measures? Most security programs rely on preventative and reactive components — establishing strong defenses against the attacks those tools know exist. On the other hand, proactive security measures include implementing incident response policies and procedures and proactively hunting for hidden/unknown attacks.

Here are a few simple rules to help govern your approach to cybersecurity with a preventative, reactive, and proactive mindset:

• Assume you’re breached and begin your offensive (proactive) initiatives with the goal of finding those breaches. By doing so, you’ll seek to validate the strength of your defensive/prevention tools with the understanding that none of them are 100% effective.
• Use asset discovery tools to discover the hosts, systems, servers, and applications within your network environment, because you can’t protect what you don’t know exists.
• Execute regular compromise assessments (we recommend at least once a week) and inspect every asset residing on your network.
• Define security policies and procedures, and implement educational/training requirements so your entire team knows what to do in the event you discover a hidden breach, or worse, fall victim to a data breach.
• Time is your most valuable asset, so implementing tools/technology to increase your speed of detection and time to respond are key and can help your security team prevent a data breach.

If your team lacks the resources to proactively detect and respond to advanced persistent threats, consider outsourcing your security services to a Managed Detection and Response (MDR) provider. MDR companies independently advise and alert you of immediate threats and provide assistance in responding to and eliminating those threats.

Contact us to learn more about managed detection and incident response services.