ALT-2434 · Entra ID
Legacy authentication protocol usage spike
IMAP4 authentication attempts increased 8x versus the weekly baseline.
lowClosedconfidence 67% · 1969-12-31 19:32:00Z · rule DET-0091 Legacy Auth Usage
Detection summary
IMAP4 authentication attempts increased 8x versus the weekly baseline.
- Affected host
- WS-ENG-231
- Affected user
- a.pratama
- Source IP
- 10.20.29.11
- Detection rule
- DET-0091 Legacy Auth Usage
- Log source
- Entra ID
- Assignee
- R. Wijaya
Recommended actions
- Confirm whether a legacy client was deployed
- Plan legacy auth blocking
Analyst decision
Triage checklist
- 1. Confirm the detection logic matched genuine activity.
- 2. Check user and asset context for expected behaviour.
- 3. Pivot on host, user, IP and hash in the Log Explorer.
- 4. Enrich IOCs with threat intelligence.
- 5. Set a verdict and record your reasoning.