What is Network Traffic Analysis (NTA): Importance and Methods

What Is Network Traffic Analysis?

Network traffic analysis (NTA) is a method of monitoring network traffic to identify malicious activity or other network issues caused by application bottlenecks, connectivity issues, and so on.

Key steps in network traffic analysis include:

• Capturing network data by placing sensors at strategic points like routers, switches, or cloud gateways. These sensors collect critical information, including packet headers, payloads, and session metadata.
• Analyzing network behavior using rule-based detection or advanced machine learning to separate normal activity from anything suspicious or harmful.
• Alerting security teams when something unusual occurs, for example, a workstation transmitting large amounts of data to an unknown external server.
• Providing real-time network visibility so threats can’t hide in the noise of routine traffic.

Using network traffic analysis tools, your organization can quickly detect and respond to cyber threats, maintain network health, and comply with information security regulations.

Evolution of Network Traffic Analysis

Network traffic analysis has evolved from simple packet sniffing into an AI-powered cybersecurity component, forming the backbone of comprehensive Network Detection and Response (NDR) platforms.

1980s–1990s: Administrators relied on basic packet-capture tools (like tcpdump) mainly for manual troubleshooting, not security.

1990s–2000s: The development of intrusion detection systems (IDS) automated threat detection using signature-based matching, effective against known threats but weak against newer ones.

2000s–2010s: Shifted toward behavior-based anomaly detection to spot unknown threats by identifying deviations from standard traffic patterns.

2019: Gartner’s Market Guide for Network Traffic Analysis formally recognized NTA solutions as an emerging security category for threat detection.

2020s: NTA evolved into NDR, integrating:

• Historical data storage
• Real-time analytics and AI-driven threat detection
• Integrated threat intelligence
• Automated response features

The following factors drove the growth of web traffic analysis:

• Increasing network complexity: Organizations are increasingly operating hybrid infrastructures (on-premises, remote, and multi-cloud environments), with approximately 75.44 billion IoT devices online in 2025.
• Widespread web encryption: With over 70% of web traffic encrypted, older network monitoring methods faced visibility issues. Modern NTA solutions are adapted by analyzing encrypted traffic through metadata analysis or secure decryption.
• Remote work and cloud adoption: The shift to cloud services has increased demand for real-time, intelligent network monitoring across distributed environments. High-maturity security teams use network traffic analysis tools as a key layer in their SOC, alongside endpoint and log monitoring, to cover new threat vectors.

How Does Network Traffic Analysis Work?

NTA solutions use machine learning, behavioral analysis, threat-hunting rules, and scanning for Indicators of Compromise (IOCs) to detect abnormalities in network traffic. The acquired data is compared to the baseline, which represents normal network behavior.

Two network traffic analysis methods are used in NTA software:

• Packet analysis: The NTA solution captures, decodes, and analyzes the data packets sent over a network. This approach allows analysts to obtain more data and is especially helpful for investigative and diagnostic purposes.
• Flow data analysis: This type of network analysis uses flow data or flow records of the network connections to identify unauthorized communication between the network elements. With better scalability, this approach works well for detecting exfiltrations.

Here are the main differences at a glance:

Importance and Benefits of Network Traffic Analysis

Even if attackers bypass antivirus or endpoint defenses, their actions still leave traces in your network. Network traffic analysis is important because it shows the hidden pathways that attackers travel. This enables organizations to detect and respond to potential threats before they escalate.

Unlike endpoint-centric tools, which only see individual devices, NTA solutions improve your security by offering complete visibility between all systems, including unmanaged devices, IoT gear, or rogue machines that slip into your network.

Key benefits of network traffic analysis include:

1. Faster incident detection and response

NTA enables security teams to quickly detect and respond to threats like ransomware attacks before extensive damage occurs. This faster incident detection helps reduce dwell time, the period between initial compromise and detection when an attacker lurks in your network.

It continuously monitors network activity to identify suspicious patterns, such as unusual port scans or unexpected communications between internal and external servers.

During a ransomware attack, NTA collects and analyzes detailed network metadata. This lets your analysts identify when and how an attacker gained entry. Your security team can then reconstruct attack timelines, trace lateral movements between compromised systems, and identify the attacker’s tactics in near real time.

2. Internal threat and anomaly detection

NTA strengthens cybersecurity by catching insider threats, suspicious user activities, and violations of security policies. If an employee suddenly accesses sensitive files outside normal hours or installs unauthorized software, NTA alerts your security team to investigate.

This continuous network traffic monitoring helps identify compromised credentials and malware spreading internally.

3. Proactive threat hunting

Beyond automated alerts, network traffic monitoring and analysis help to test hypotheses about network compromise. If security analysts notice repeated traffic spikes toward an unknown IP address, NTA lets them dig deeper and uncover potential hidden malware activity.

4.Enhanced threat intelligence

Network traffic analysis tools boost threat intelligence capabilities by identifying malicious domains, extracting IoCs, and analyzing packet headers for suspicious content. Real-time insights help your security team to update defenses, refine security policies, and prevent potential threats before they impact your network

5. Network troubleshooting

With the help of NTA tools, IT specialists can identify and diagnose issues with network performance. For instance, NTA solutions are good at identifying applications that consume large amounts of bandwidth.

6. Compliance monitoring and reporting

Frameworks and regulations (from PCI DSS to NIST guidelines) expect organizations to monitor network activity for suspicious events. NTA solutions make it easier for organizations to generate the logs and reports auditors require. For example, it could be showing which users accessed sensitive systems and when.

With IBM reporting that the global average cost of a data breach will surpass $4.88 million in 2024, detecting threats early has never been more critical. Organizations applying AI and automation to security prevention, including web traffic analysis tools, saved an average of $2.22 million compared to those without these technologies.

▶️ To learn more about how network data assists in investigations, our article on the best digital forensics tools covers techniques for analyzing evidence from networks and devices.

Network Traffic Analysis vs. IDS/IPS vs. NDR: Key Differences

Network traffic analysis, network detection and response (NDR), and intrusion detection and prevention systems (IDS/IPS) are classes of solutions for network traffic analysis. Yet there are differences between these types of software.

Network Traffic Analysis

• NTA tools monitor and analyze your network traffic to spot unusual patterns or malicious activities.
• They inspect network data across the environment (internal and external) and use a combination of rule-based and behavioral analysis to detect threats or performance issues.
• NTA solutions focus on visibility and detection rather than blocking by offering rich context and alerts, which analysts can then use to investigate incidents and hunt for threats.

Intrusion Detection/Prevention Systems (IDS/IPS)

• An IDS monitors network traffic and triggers alerts when traffic matches known attack signatures or violates specific rules. For example, if a known malware pattern or a disallowed protocol is detected, the IDS logs it and alerts the security team.
• An IPS takes this a step further by blocking or rejecting malicious traffic as it flows through.
• IDS and IPS are high-speed and preventative, but they rely on predefined patterns to catch threats and can miss new anomalies. If not tuned well, they also tend to generate more false positives.

Network Detection and Response

• NDR solutions are the next generation of network security tools. They build upon the NTA and IDS concepts, combining their strengths into a unified platform.
• NDR platforms store and correlate historical network metadata, incorporate advanced analytics, and can automate responses to threats. For example, the platform might notice suspicious lateral movement in the network and can automatically isolate the affected system by interacting with a network access control or endpoint agent.
• NDR aims to provide a more complete incident storyline and even handle some remediation by adding anomaly detection, host insights, and automated alert triage.

While some sources may use these terms interchangeably, the key is understanding that NTA tools focus on analysis, IDS/IPS on prevention of known threats, and NDR on a holistic detect-and-respond approach leveraging network data.

How Organizations Use Network Traffic Analysis to Improve Security

Many organizations start using network traffic analysis for threat detection and end up implementing it for multiple purposes across security and IT operations. Here are a few common use cases where NTA tools can help strengthen your security defenses:

Advanced threat detection and APT monitoring

NTA solutions catch Advanced Persistent Threats (APTs) by spotting subtle anomalies in network behavior. For example, NTA can detect command-and-control traffic from malware (even if it’s using uncommon ports or encryption) or find patterns indicative of a slow data exfiltration that other tools might ignore.

You can monitor for zero-day attacks, fileless malware, and covert channels that evade traditional signature-based defenses.

Lateral movement and internal reconnaissance

Security teams use NTA to catch lateral movement early by flagging unusual connections between internal hosts, such as one server suddenly scanning the entire subnet using a Server Message Block (SMB).

This use case is important in large flat networks, where intruders could otherwise roam freely. NTA adds a layer of segmentation detection, alerting on cross-segment traffic that looks suspicious.

Data exfiltration and insider data theft

NTA solutions can be configured to alert on large outbound data transfers, unusual file uploads, or even specific keywords in outgoing traffic (if doing deep packet inspection). Similarly, if an insider is stealing data, they often generate abnormal network flows (like mass database queries or sending files to their personal email or a Dropbox).

NTA can catch these patterns and alert security teams to intervene. Security teams also use network traffic analysis as a backstop for DLP (Data Loss Prevention) controls to determine where endpoint DLP might fail.

Incident investigation and forensics

If malware was found on a device, analysts can comb through NTA logs to identify when that device first contacted the attacker’s server, what other machines it communicated with (to check if the infection spread), and what data may have been transmitted.

You can also use NTA to monitor if an attacker is still present or attempting to exfiltrate data while the incident response is ongoing.

Network operations and performance monitoring

Network traffic analysis tools keep your network efficient and reliable by identifying performance bottlenecks, outages, or misconfigurations. For example, if an application runs slowly, NTA can reveal that a particular link is saturated or a backend service isn’t responding to requests.

These tools include dashboards for network utilization, top talkers, error rates, etc., which engineers use for capacity planning and troubleshooting.

Implementing an Effective Network Traffic Analysis Solution

NTA solutions use either flow-based methods (analyzing summarized metadata about network communications) or Deep Packet Inspection (DPI) (capturing and inspecting complete packets for detailed insights).

Flow-based solutions are efficient and scalable but offer less granular visibility, while DPI tools provide deeper inspection but require more resources and storage. When implementing an NTA solution, keep the following considerations in mind:

Data sources (flow vs. packet)

• Determine if your network devices can generate flow data (NetFlow, IPFIX) or if you’ll need raw packet capture via SPAN ports or taps.
• Flow-based solutions need flow-enabled network devices, while DPI can ingest raw traffic from any managed switch.
• Choose based on available infrastructure and desired visibility level.

Agent-based vs. agent-free deployment

• Agent-based solutions require sensors installed directly on endpoints or network segments, capturing detailed traffic data but increasing complexity.
• Agent-free solutions passively ingest data via network taps or flow exports without endpoint installations.
• Prioritize deploying sensors strategically, at internet gateways or critical network segments to maximize visibility without overwhelming your team.

Real-time vs. historical data

• Real-time analytics enable quick threat detection, while historical data retention supports incident investigations over time.
• Some NTA tools don’t retain long-term data, or they price storage separately, increasing costs.
• Clearly define your real-time detection needs versus historical analysis requirements to choose an NTA solution with the proper storage and retention capabilities

Full packet capture vs. metadata extraction

• Full packet capture provides detailed forensic evidence but requires extensive resources, storage, and management.
• Metadata extraction offers a practical compromise, capturing packet details and protocol metadata without storing entire payloads.
• We recommend selectively using full capture for high-risk network segments and relying on metadata extraction elsewhere to balance visibility and cost.

Encrypted traffic visibility

• Use an NTA solution that excels at analyzing encrypted traffic patterns, such as analyzing metadata and behavioral indicators, to detect threats.
• Decryption can be done carefully to avoid violating privacy or compliance policies by focusing on traffic where your organization owns both ends (like servers serving clients).
• You can look at packet sizes, session lengths, or TLS certificates used (JA3 fingerprinting) to identify suspicious behavior without needing plaintext access.

Deployment coverage

• Place sensors at key network junctions, such as internet gateways, internal switches, and cloud infrastructure, to ensure your NTA solution covers both inbound/outbound (north-south) and internal (east-west) network traffic.
• Prioritize initial deployments around sensitive assets or common attack pathways, then gradually expand to prevent attackers from exploiting unmonitored areas.

Integration with security systems

• Streamline incident response by automatically feeding NTA alerts into your Security Information and Event Management (SIEM) system. This enables rapid correlation with logs from endpoints, servers, and critical apps, speeding up threat detection and response.
• Incorporate real-time threat intelligence feeds into your NTA solution to understand incidents better. For example, Group-IB’s Threat Intelligence platform tracks over 900 threat actors and their campaigns to provide security teams with context around flagged communications, suspicious IPs, and blacklisted domains.
• Combine NTA alerts with Security Orchestration, Automation, and Response (SOAR) platforms or endpoint isolation tools. When NTA detects a high-confidence threat, it can trigger automated containment and remediation, saving your organization precious time.

Does Group-IB Provide Network Traffic Analysis Software?

Integrating network traffic analysis into your security ecosystem can transform isolated network traffic data into actionable insights. This approach gives your security team comprehensive threat intelligence, improved digital risk management, and automated response capabilities. You’ll be able to detect threats earlier, understand incidents better, and respond faster.

At Group-IB, we’ve built a powerful network traffic analysis functionality into our Managed XDR solution. The NTA module provides complete visibility into what’s happening across your network, allowing you to:

• Identify when infected devices communicate with malicious command-and-control (C&C) servers.
• Quickly discover unusual device or user behavior inside your network.
• Recognize network anomalies that indicate attackers moving between systems.
• Optimize defenses by automatically correlating network data with Group-IB’s Threat Intelligence Platform.

Other modules include the Malware Detonation Platform for in-depth analysis of suspicious files, Endpoint Detection and Response functionality, and more.

Together, these integrated capabilities help simplify threat detection and incident investigations, ensuring your organization stays ahead of network threats that would otherwise go undetected.

Learn more about Group-IB’s Managed XDR solution.