What evidence do auditors commonly ask for on AC-2(12) Account Management | Account Monitoring for Atypical Usage?

Access control policy; Procedures addressing account management; System design documentation; System configuration settings and associated documentation; System monitoring records; System audit records.

What is the most common gap auditors find on AC-2(12)?

Atypical usage of system accounts was never defined, so monitoring cannot distinguish abnormal logon times, locations or volumes

NIST SP 800-53 Rev 5 · AC - Access Control

`AC-2(12)` Account Management | Account Monitoring for Atypical Usage

(a) Monitor system accounts for organization-defined atypical usage; and (b) Report atypical usage of system accounts to organization-defined personnel or roles.

Source: NIST SP 800-53 Rev 5, AC-2(12). 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 NIST SP 800-53 Rev 5 in the compliance library.

Base controls and their enhancements. Which apply follows the baseline you are assessed against (for example FedRAMP Moderate or High, or the low, moderate and high baselines of SP 800-53B). Text in square brackets is a parameter your organisation sets.

artefacts

held by a system

at each review

hard

to go live

Policy repository / GRC workspace

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

System monitoring records · Identity provider / directory

periodic reviewEvidence produced at each review

System audit records · Identity provider / directory
Audit tracking and monitoring reports · Identity provider / directory
Privacy impact assessment · Identity provider / directory
Test of Mechanisms implementing account management functions · Identity provider / directory

governing documentDocuments that govern the control

Access control policy · Policy repository / GRC workspace
Procedures addressing account management · Policy repository / GRC workspace
System design documentation · Policy repository / GRC workspace
System configuration settings and associated documentation · Policy repository / GRC workspace
System security plan · Policy repository / GRC workspace

First move

Mostly documents and reviews. Pull the 1 system-held artefact from your Identity provider / directory on a schedule; put the documents under version control with an owner and review date, and log each review as a dated record with a named reviewer.

Common gaps auditors find

Atypical usage of system accounts was never defined, so monitoring cannot distinguish abnormal logon times, locations or volumes
Detected atypical account usage under (b) is not reported to the organization-defined personnel or roles for follow-up

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

AC-2(11) Account Management | Usage Conditions · AC-2(13) Account Management | Disable Accounts for High-risk Individuals