Why are Next Generation Firewalls (NGFW)—which significantly outperform traditional firewalls—not sufficient on their own to stop automated, distributed polymorphic attacks launched from thousands of IPs? And why are tools like Exabai’s cyber guardian, which manages dynamic and contextual offensive IP lists, critical to an effective defense?

What Are Next Generation Firewalls (NGFW)?

Next Generation Firewalls are an evolution of traditional firewalls. In addition to filtering traffic by IP, port, and protocol, they offer:

• Deep Packet Inspection (DPI)

• Integration with IDS/IPS systems

• Application-layer filtering (traffic control by type: social media, VoIP, etc.)

• Known malware signature analysis

• Smarter and more adaptable rule sets

It sounds like a lot, but…

Why Aren’t They Enough Against Distributed Polymorphic Attacks?

Let’s break it down.

1. They Cannot Independently Handle Dynamic and Large-Scale Offensive IPs

NGFWs do not maintain their own real-time, contextualized database of offensive IP addresses. Instead, they depend on:

• Static or third-party lists, which may be outdated or fail to cover emerging attacks

• Generalized threat information, not contextualized for your specific infrastructure

• No ability to learn in real time who is attacking your environment

Result:
If a botnet launches an attack from 100,000 new or rotating IPs, it’s unlikely the NGFW will block them in time—unless someone or something tells it which ones they are.

2. Polymorphism Bypasses Signature-Based Detection

NGFWs use malware signatures to detect threats. However:

• Malicious code changes with each request

• Payloads vary slightly every time

• Bots use encoding, fragmentation, and obfuscation techniques

• Many attacks stay below detection thresholds

Result:
The NGFW sees what appears to be distinct traffic every time—even though it’s part of the same automated attack → it fails to detect it as a correlated threat.

3. Distributed Attacks Evade Volume- or Frequency-Based Detection

NGFWs can enforce rate-limiting policies, but:

• Each bot sends very few requests (maybe 1 every 10 seconds)

• They stay under alert thresholds

• Distribution causes the overall pattern to go unnoticed

Result:
Behavior-based detection by volume is bypassed. The firewall simply sees “normal users” making occasional requests.

4. No External Threat Context

NGFWs don’t “know” if an IP that accessed your system today is already attacking another organization. They lack:

• Real-time collective threat intelligence

• Dynamic connections to contextualized threat intelligence networks

• The ability to act based on external, crowdsourced threat analysis

Why Is a Cyber Guardian Like Exabai’s Essential?

A system like Exabai’s Cyber Guardian, which acts as a perimeter security layer, provides a vital defense capability through:

1. Dynamic, Automated Blacklist Management

• Collects and updates a list of confirmed offensive IPs in real time

• Applies this intelligence to the organization’s specific environment

• Makes decisions based on current, real-world, and tailored threats

2. Predictive Blocking Using Collective Intelligence

• Analyzes global attack and botnet behavior

• Detects trends that haven’t yet reached your network

• Acts proactively to block IPs that are likely to attack

3. Correlation and Continuous Learning

• Analyzes behavioral patterns not visible to NGFWs

• Recognizes polymorphic attempts as part of a unified malicious pattern

• Adjusts its response and feeds updates to the firewall or WAF to block new variants

4. Orchestration with Existing Infrastructure

• Integrates with NGFWs, SIEMs, WAFs, and load balancers

• Applies automated blocking without manual intervention

• Reduces false positives through contextual network and behavioral analysis

Conclusion