Suspicious Entra Device Code Authentication with Office Client and Automated User Agent

ATT&CK techniques

Initial Access → Lateral Movement

Recon
Resource Dev
Initial Access
- T1566.002Spearphishing Link
Execution
Persistence
Priv Esc
Defense Evasion
- T1550.001Application Access Token
Cred Access
- T1528Steal Application Access Token
Discovery
Lateral Movement
- T1550.001Application Access Token
Collection
C2
Exfiltration
Impact

What it detects

This rule detects Entra ID sign-ins using the device code authentication flow against the Microsoft Office client application from an automated python-requests user agent, matching the Kali365 device code phishing ecosystem. Adversaries phish device codes to obtain refresh tokens for the well-known Office client and replay them programmatically to access mailboxes. Device code flow paired with a scripted user agent is a strong indicator of token theft and mailbox compromise.

Reporting behind it

Related detections9 linkedT1550.001 — drag to rearrange

Malicious PRT Token Forging via AADInternals (via ps_script)

Suspicious AWS SSO Token Creation and Role Credential Retrieval (via cloudtrail)

Malicious OAuth Application Granted Full Mailbox and EWS Permissions (via m365)

Suspicious Kubernetes Service Account Token Generation via kubectl

Suspicious browsercore Execution from Anomalous Parent for PRT Cookie (via process_creation)

Suspicious GAM OAuth Token Enumeration via Process Creation

Suspicious AWS SSO Account Role Enumeration via ListAccountRoles (via cloudtrail)

Suspicious AWS Federated Console Login From Programmatic Credentials

Suspicious Device Registration Following OAuth Token Theft

Suspicious Entra Device Code Authentication with Office Client and Automated User Agent

Pivot detection · T1550.001 · 9 related

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

Full detection rule

Unlock this rule to view and copy it

The detection logic is included with a plan. Everything else — context, mappings and implementation details — stays free on this page.

Sign in for 3 free unlocks

Signing in gives you 3 unlocks to spend on any rule in the library. No card, and they do not expire.

Also included

Unlocked rules convert on this page — to Splunk SPL or Splunk — Raw Index SPL or Microsoft Sentinel KQL or Microsoft Sentinel ASIM ASIM KQL or Microsoft Defender XDR KQL or Elastic Security KQL or Elastic Security Lucene or Elastic Security ES|QL or CrowdStrike Falcon CQL or SentinelOne PowerQuery or Palo Alto Cortex XDR XQL or Carbon Black Cloud Platform Search or Carbon Black EDR Process Search or Google Security Operations UDM Search or IBM QRadar AQL or Sumo Logic Cloud SIEM Rules expression or Rapid7 InsightIDR LEQL or Graylog Search or OpenSearch Lucene or OpenSearch PPL PPL or Grafana Loki LogQL or SQLite SQL or Zircolite SQLite — with the log-source profile the engine picked, the field map it used, and everything it could not express. Converting a rule you have unlocked costs no further credit.

See it run on a free rule →Convert your own rule →