Communications analysis is the examination of network traffic, signalling or message content to understand who is talking to whom, how often and with what patterns. In security work it is used to identify anomalies, map dependencies or detect command and control activity by studying metadata, protocols and payloads where available.
How communications analysis works
Communications analysis studies the observable structure of traffic, messages, and signalling so defenders can understand communication relationships without relying on content alone. It focuses on patterns such as direction, frequency, timing, protocol choice, and repetition, which often reveal operational behaviour even when payloads are encrypted or partially hidden.
That makes it useful in environments where the important question is not only what was said, but which entities exchanged data, when the exchange happened, and whether the pattern matches an expected business process, service dependency, or user workflow.
What communications analysis reveals
The technique can expose recurring dependencies between hosts, applications, and external services, which helps teams build a practical map of normal communications. Once that baseline exists, deviations such as new destinations, unusual burst patterns, or abnormal signalling sequences become easier to spot.
In security operations, this visibility is valuable because many incidents first appear as a change in communication behaviour rather than a clear malicious payload. Analysts may use it to separate routine chatter from suspicious beaconing, lateral movement, or unexpected command paths.
Why metadata and protocol context matter
Communications analysis does not depend on full message disclosure to be useful. Metadata such as source, destination, port, timing, size, and protocol family can still support strong conclusions about trust relationships, access paths, and service dependencies, especially where payload inspection is unavailable or undesirable.
Protocol context adds another layer of meaning. The same traffic volume can mean very different things depending on whether it is DNS, HTTP, SMTP, messaging, or a custom signalling channel, so effective analysis combines raw network observation with knowledge of normal protocol behaviour and application intent.
Communications analysis in detection and response
Defenders use communications analysis to identify anomalies, investigate suspicious connections, and reconstruct activity after an alert. It is especially helpful when an adversary blends into ordinary traffic, because repeated timing patterns, rare endpoints, and unusual conversation pairs can still stand out.
It also supports response work after an intrusion has been contained. By reviewing communication flows, teams can identify likely staging points, exposed dependencies, and other systems that may have interacted with the same channel, which helps narrow the scope of compromise and improve containment decisions.
Risk and Threat Considerations
Communications analysis matters because the communication layer often becomes a source of stealth for adversaries. If defenders cannot see abnormal talking patterns, hostile activity can blend into normal service traffic, hide command and control, or mask dependency abuse across trusted network paths.
Failure mechanism: Encrypted payloads, noisy environments, and high-volume routine traffic can obscure malicious patterns, leaving defenders with weak visibility into who is communicating, how often, and for what purpose.
Impact: That gap can delay detection of intrusion, lateral movement, exfiltration, or persistent beaconing, and it can also leave dependency mapping incomplete when organisations need it most.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
MITRE ATT&CK addresses the attack and risk surface, while NIST CSF 2.0 sets the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| NIST CSF 2.0 | DE.CM-01 — Monitoring for Anomalies and Events | Communications analysis directly supports anomaly monitoring in network traffic. |
| ID.AM-01 — Physical Devices and Systems Inventory | Communications analysis depends on knowing which assets and connections should exist. | |
| Recommendation — Monitor network communications for unusual patterns and investigate deviations from baseline. Maintain asset and connection inventories so observed traffic can be compared to expected relationships. | ||
| MITRE ATT&CK | T1071 — Application Layer Protocol | Communications analysis often looks for command and control activity hidden in common protocols. |
| T1021 — Remote Services | Traffic pattern review helps detect unexpected remote access and lateral movement over trusted services. | |
| Recommendation — Map suspicious protocol use to T1071 and hunt for command and control patterns in traffic. Correlate remote service traffic with T1021 to identify lateral movement and abnormal access paths. | ||
Practitioner Guidance
Why practitioners should care: Treat communications analysis as a baseline discipline, not a one-off investigation technique. The value comes from knowing what normal exchange patterns look like before an incident forces you to interpret them under pressure.
What to watch for: Focus on new peer relationships, unusual timing regularity, rare protocol combinations, and destinations that do not fit the expected application or business process. Those are often the highest-signal deviations in real environments.
Practitioner takeaway: The strongest communications analysis programs combine traffic observation with asset context, so the same pattern can be judged against both network behaviour and expected service relationships.
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Reviewed and updated by the NHIMG editorial team on October 29, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org