What evidence do auditors commonly ask for on NS-4 Deploy intrusion detection/intrusion prevention systems (IDS/IPS)?

IDS/IPS deployment topology showing inspected traffic paths; Rule set and tuning history; Alert forwarding configuration into the SIEM; False positive rate trend.

What is the most common gap auditors find on NS-4?

IDS deployed but alerts never routed to an analyst

Azure Security Benchmark v3 (renamed Microsoft cloud security benchmark) · Network Security

`NS-4` Deploy intrusion detection/intrusion prevention systems (IDS/IPS)

Deploy network intrusion detection and prevention capability that inspects traffic and payload to and from the workload, tuned so the alerts it raises are usable by the security operations team.

Source: Azure Security Benchmark v3 (renamed Microsoft cloud security benchmark), NS-4. The statement above is our statement of the clause, read from the published text and cited so you can check it against the official text, not the instrument verbatim. Open Azure Security Benchmark v3 (renamed Microsoft cloud security benchmark) in the compliance library.

artefacts

held by a system

at each review

easy

to go live

SIEM / log platform

where the evidence lives

teal = a system already holds it · olive = produced at each review. To go live: easy when half or more of the artefacts are already held by a system, moderate from a quarter to a half, hard below a quarter.

These are the artefacts auditors commonly ask for on this requirement, our guidance rather than text from the standard. Your assessor decides what is sufficient in your context, and asks for samples across the period when a report covers one.

system holds itEvidence a system already holds

Rule set and tuning history · SIEM / log platform
Alert forwarding configuration into the SIEM · SIEM / log platform

periodic reviewEvidence produced at each review

none for this control

governing documentDocuments that govern the control

IDS/IPS deployment topology showing inspected traffic paths · Policy repository / GRC workspace
False positive rate trend · Policy repository / GRC workspace

First move

Automate the pull from your SIEM / log platform. Retention and alert rules exported from the SIEM; review evidence is the closed-alert record with reviewer and time.

Common gaps auditors find

IDS deployed but alerts never routed to an analyst
default rule set never tuned so alerts are ignored
encrypted traffic paths not inspected and not compensated

Do this for your whole sheet

Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.

Build my evidence sheet

NS-3 Deploy firewall at the edge of enterprise network · NS-5 Deploy DDOS protection