Audit Logging for CMMC: The 3.3 Family Made Simple

The 3.3 audit family asks four things: log the right events, keep them, protect them, and actually look. Two controls are 5-pointers — and "we have logs" fails without the looking.

If there's one area where small contractors quietly fall short, it's audit logging. Not because it's hard, but because "we have logs" feels like enough — and it isn't. The NIST 800-171 audit family (3.3) is really asking four things: log the right events, keep them, protect them, and look at them. Here's the family in plain English.

9Controls (3.3 family)

2Are 5-point

4Things it asks

What the 3.3 family actually requires

Control	In plain English
3.3.1 (5 pts)	Create and retain the logs you need to investigate activity — across the whole in-scope environment.
3.3.2	Tie every logged action to a specific person (no shared accounts).
3.3.3	Periodically review and update what you log.
3.3.4	Alert if logging itself fails.
3.3.5 (5 pts)	Correlate and review the logs to spot suspicious activity — actually use them.
3.3.6	Be able to search logs and generate reports on demand.
3.3.7	Sync system clocks so time stamps line up.
3.3.8	Protect logs and logging tools from tampering or deletion.
3.3.9	Limit who can manage the logging functions.

Why teams fail it

Three patterns show up again and again:

Partial coverage. Logging is on for the domain controller but not the file server, or the firewall but not the endpoints. The requirement is the whole in-scope environment.
No retention. Logs roll over in a few days. If you can't produce 90 days (or whatever your policy says) during an investigation, you don't really have audit logs.
Nobody looks. The two 5-point controls here (3.3.1 and 3.3.5) reward generating and reviewing logs. Storage without review protects no one — and assessors ask to see your review process.

The straightforward fix

You don't need an enterprise SOC. A small contractor can satisfy the whole family with a sensible setup:

Step 1 · Centralize

One log repository

Ship logs off every system into a SIEM or cloud log analytics — covers coverage, protection, and reporting at once.

Step 2 · Retain & protect

Keep and lock them

Set retention in policy, and make sure the people generating logs can't delete them (3.3.8 / 3.3.9).

Step 3 · Sync & review

Clocks + a cadence

Point everything at an NTP source, then run a documented periodic review — that's the "actually look" requirement.

Centralize. Ship logs off each system into one place (a SIEM, or your cloud platform's log analytics). Central collection covers coverage, protection (3.3.8), and reporting (3.3.6) in one move.
Set retention. Define how long you keep logs in policy, and configure storage to match.
Restrict + protect. Make sure the people generating logs can't delete them, and limit who manages logging (3.3.8 / 3.3.9).
Sync clocks. Point everything at an authoritative NTP source (3.3.7).
Review on a cadence. Even a documented weekly review with notes satisfies the "actually look" requirement — and an alert when logging breaks (3.3.4) closes the loop.

The single most valuable move is central collection. One log repository turns "we have logs scattered on every box" into a coverage story, a protection story, and a reporting story an assessor can verify in minutes. See the full breakdowns in the Control Library.

See what audit logging is worth to your score

3.3.1 and 3.3.5 are 5-point controls. Run all 110 free and see where the audit family puts your number.

Calculate your SPRS score →

Start here

Centralize your logs, set retention, restrict access, sync clocks, and review on a cadence — that's the whole family. Score yourself, then document it in your SSP. Both tools are free.