Suspicious OAuth Application Registration with Localhost Reply URL via Azure AD

ATT&CK techniques

Initial Access → Cred Access

Recon
Resource Dev
Initial Access
- T1078.004Cloud Accounts
Execution
Persistence
- T1078.004Cloud Accounts
Priv Esc
- T1078.004Cloud Accounts
Defense Evasion
- T1078.004Cloud Accounts
Cred Access
- T1528Steal Application Access Token
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects registration or update of an Azure AD OAuth application whose reply or redirect URL points to an anomalous localhost loopback endpoint such as http://localhost:7823/access/. This behavior was observed in OAuth application attacks researched by Huntress where adversaries register illicit applications to harvest tokens. Attackers abuse consented OAuth apps to maintain persistent access to cloud mailboxes and data, so anomalous reply URLs are a strong early indicator of illicit app registration.

Reporting behind it

Related detections9 linkedT1078.004 — drag to rearrange

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Suspicious SES Account Sending Enablement and Identity Verification via CloudTrail

Possible Stolen AWS Credential Validation via STS GetCallerIdentity

Suspicious AWS Federated Console Login From Programmatic Credentials

Suspicious Entra ID Device Code Flow Authentication

Suspicious M365 Legacy Authentication via BAV2ROPC Client via m365

Suspicious OAuth Application Registration with Localhost Reply URL via Azure AD

Pivot detection · T1078.004 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

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