From the Field: Group Membership Control

๐Ÿ”Ž ๐—™๐—ฟ๐—ผ๐—บ ๐˜๐—ต๐—ฒ ๐—™๐—ถ๐—ฒ๐—น๐—ฑ โ€” Real-World Findings from Security Assessments

๐Ÿ’ฅ ๐Ÿฑ๐Ÿฎ.๐Ÿฐ%ย of infrastructures Iโ€™ve assessed stillย ๐—บ๐—ฎ๐—ป๐˜‚๐—ฎ๐—น๐—น๐˜† ๐—ฐ๐—ผ๐—ป๐˜๐—ฟ๐—ผ๐—น ๐—น๐—ผ๐—ฐ๐—ฎ๐—น ๐—ด๐—ฟ๐—ผ๐˜‚๐—ฝ ๐—บ๐—ฒ๐—บ๐—ฏ๐—ฒ๐—ฟ๐˜€๐—ต๐—ถ๐—ฝ.

I often see GPOs used for things like adding shortcuts, enabling exceptions, or tweaking minor UI settings โ€” ๐—ฏ๐˜‚๐˜ ๐—ฟ๐—ฎ๐—ฟ๐—ฒ๐—น๐˜† ๐—ณ๐—ผ๐—ฟ ๐—ฒ๐—ป๐—ณ๐—ผ๐—ฟ๐—ฐ๐—ถ๐—ป๐—ด ๐—ฟ๐—ฒ๐—ฎ๐—น ๐˜€๐—ฒ๐—ฐ๐˜‚๐—ฟ๐—ถ๐˜๐˜†ย standards across the environment.

โœ… This includesย controlling membership in local groupsย on endpoints and servers, which is a simple way to improve your security posture.

Withย Group Policy, you can make sure memberships stay exactly as you define them โ€” and if someone changes it manually, itโ€™s reset at the next policy refresh (~every 120 mins).

๐—›๐—ผ๐˜„ ๐˜๐—ผ ๐—ฑ๐—ผ ๐—ถ๐˜:

๐Ÿ”นย Restricted Groupsย โ€“ Strictly enforce exact membership.

๐Ÿ”นย Group Policy Preferences (Local Users & Groups)ย โ€“ More granular targeting, control individual accounts.

๐—ฅ๐—ฒ๐—ฐ๐—ผ๐—บ๐—บ๐—ฒ๐—ป๐—ฑ๐—ฎ๐˜๐—ถ๐—ผ๐—ป:

1๏ธโƒฃ Start with a higher-level GPO (e.g., root of Tier 1) defining exactly who should be inย local Administratorsย โ€” and remove everyone else.

2๏ธโƒฃ Add exceptions (e.g., service accounts) lower in the OU structure with โ€œaddโ€ rules only.

๐—ฅ๐—ฒ๐˜€๐˜‚๐—น๐˜:ย A consistent, enforced, and secure local group membership across your entire environment.