Identity Threats: Entra & Defender for Identity
Compromised identities are behind most breaches. Learn how to investigate and remediate compromised accounts from Microsoft Entra ID and lateral movement alerts from Defender for Identity.
Why identity is the new perimeter
Firewalls protect the building. Identity protects the person.
In a world where employees work from home, coffee shops, and airports, the network perimeter is meaningless. What matters is: who is logging in, from where, and is it really them?
Entra ID (Microsoft’s cloud identity service) detects compromised cloud accounts — impossible travel, password spray, token theft. Defender for Identity watches your on-premises Active Directory for lateral movement, credential theft, and reconnaissance.
Together, they cover the full identity attack surface: cloud + on-premises.
Entra ID: cloud identity threats
Common Entra ID risk detections
| Detection | What It Means | Risk Level |
|---|---|---|
| Impossible travel | User signs in from New Zealand, then Germany 30 minutes later | High |
| Password spray | Multiple accounts targeted with common passwords | High |
| Unfamiliar sign-in properties | New device, new browser, new location | Medium |
| Anonymous IP | Sign-in from Tor, VPN, or anonymous proxy | Medium |
| Leaked credentials | User’s credentials found in a public breach database | High |
| Token theft | Adversary-in-the-middle attack stealing session tokens | High |
| Malicious IP | Sign-in from an IP associated with known attacks | High |
Investigation workflow for compromised Entra ID accounts
- Review the risk detection — what triggered it? (impossible travel, password spray, etc.)
- Check sign-in logs — when, where, what device, what app
- Check audit logs — did the attacker change anything? (MFA methods, email forwarding rules, app consent)
- Check for lateral activity — did the account access other resources, send emails, or create apps?
- Remediate:
- Reset password
- Revoke all refresh tokens and sessions
- Re-register MFA (if MFA methods were modified)
- Review and remove suspicious app consents
- Check for inbox rules and mailbox forwarding
Scenario: James investigates impossible travel
James at Pacific Meridian sees a High-risk alert: “Impossible travel — user signed in from Auckland NZ at 9:00 AM, then from Moscow at 9:15 AM.”
Investigation:
- Sign-in logs show the Moscow sign-in used a different device and browser
- The Auckland sign-in was the user’s normal work device
- Audit logs show the Moscow session changed the user’s MFA phone number and created a mail forwarding rule to an external address
This is a confirmed account compromise.
Remediation:
- Reset password immediately
- Revoke all sessions
- Remove the malicious MFA phone number and re-register the legitimate one
- Delete the forwarding rule
- Check if any sensitive emails were forwarded before detection
- Block the Moscow IP as an indicator
Defender for Identity: on-premises threats
Common MDI detections
| Detection | Attack Technique | MITRE ATT&CK |
|---|---|---|
| LDAP reconnaissance | Attacker queries AD to map users, groups, and permissions | Discovery (T1087) |
| Kerberoasting | Request TGS tickets for service accounts to crack offline | Credential Access (T1558) |
| Pass-the-hash | Use stolen NTLM hash to authenticate without password | Lateral Movement (T1550) |
| Pass-the-ticket | Use stolen Kerberos ticket to impersonate a user | Lateral Movement (T1550) |
| DCSync | Impersonate a domain controller to replicate password hashes | Credential Access (T1003) |
| Suspicious service creation | Create a service on a remote machine for persistence | Persistence (T1543) |
| Honeytoken activity | Access to a decoy account designed to detect attackers | Early warning |
Investigation workflow for MDI alerts
- Review the MDI alert — what technique was detected? What accounts and devices are involved?
- Check the attack timeline — MDI shows the sequence of activities on the entity page
- Correlate with Entra ID — did the same user trigger cloud-side risk detections?
- Check lateral movement paths — MDI maps potential lateral movement paths through the organisation
- Remediate:
- Reset the compromised account’s password
- Rotate credentials for any service accounts involved
- Check for persistence mechanisms (scheduled tasks, services, registry keys)
- Review Group Policy for unauthorised changes
| Feature | Entra ID Protection | Defender for Identity |
|---|---|---|
| Environment | Cloud (Entra ID / Azure AD) | On-premises (Active Directory) |
| Detection method | Machine learning on sign-in telemetry | Network traffic analysis on domain controllers |
| Threats detected | Impossible travel, password spray, token theft, leaked creds | Kerberoasting, pass-the-hash, DCSync, LDAP recon, lateral movement |
| Data source | Sign-in logs, audit logs | Domain controller traffic (port mirroring or ADFS) |
| Remediation | Reset password, revoke tokens, re-register MFA | Reset passwords, rotate service account creds, check persistence |
| Integration | Feeds into Defender XDR incidents + Conditional Access | Feeds into Defender XDR incidents + Sentinel |
Exam tip: Entra ID Protection vs Defender for Identity
The exam tests whether you know which product handles which scenario:
- “User signs in from impossible location” → Entra ID Protection
- “Attacker performs pass-the-hash on domain controller” → Defender for Identity
- “Kerberoasting detected” → Defender for Identity
- “Leaked credentials found in public breach” → Entra ID Protection
- “Suspicious LDAP queries from a workstation” → Defender for Identity
Rule of thumb: if it involves sign-in behaviour or cloud tokens, it is Entra ID. If it involves AD protocols or domain controller traffic, it is MDI.
An Entra ID alert shows a user signed in from Auckland at 9:00 AM and from Moscow at 9:15 AM. The Moscow session changed the user's MFA phone number. What is the priority remediation action?
Defender for Identity detects Kerberoasting activity targeting a service account on Pacific Meridian's domain. What should James do?
🎬 Video coming soon
Next up: Identity threats are handled. Now let’s investigate shadow IT and risky cloud apps with Defender for Cloud Apps.