Active Directory Security Basics for SMEs

Why attackers go straight for AD

Active Directory holds every user account, group, and permission in your Windows environment. Compromise a Domain Admin account and an attacker effectively owns every server and workstation joined to the domain. This is why ransomware groups specifically hunt for domain admin credentials once they get an initial foothold.

The common weaknesses we find

• Too many Domain Admins. Accounts with full domain control that don't need it, often left over from past projects.
• Admin accounts used for everyday work. Checking email or browsing the web from an account with domain admin rights is a serious risk — one phishing click compromises the whole domain.
• Weak or shared service account passwords. Old service accounts with passwords that never expire and are known by too many people.
• Excessive delegation. Permissions granted broadly "to make things work" and never revisited.
• No monitoring of privileged group changes. Nobody notices when someone is added to Domain Admins.

Practical steps to reduce the risk

• Use separate accounts for admin tasks and everyday work — never browse or check email from a privileged account.
• Minimize Domain Admins. Review membership regularly and remove anyone who doesn't need it.
• Enforce MFA for any admin or remote access to domain controllers.
• Rotate and strengthen service account passwords, or use managed service accounts where supported.
• Apply the tiered administration model where practical — keep workstation admin, server admin, and domain admin separated.
• Monitor privileged group changes and unusual authentication patterns (e.g. a service account logging in interactively).
• Patch domain controllers promptly — they are high-value, high-impact targets.

Get a professional look at your AD

An internal network audit or penetration test specifically checks for privilege escalation paths in Active Directory — the exact routes a real attacker would use.