Start with the alert
Identify the user, source IP, destination system, timestamp and detection reason.
RR CYBERLAB • SOC Investigation
How to Investigate a Suspicious Login
Use a repeatable workflow for investigating suspicious authentication activity.
QUICK READ
Start with the key points below. If you want the deeper technical context, work through the investigation sections.
Build the timeline
Check failed logins, successful authentication, MFA events and activity immediately after the login.
Correlate evidence
Use authentication logs, endpoint telemetry and network activity to determine what happened next.
Consider legitimate explanations
Admin work, VPN access, service accounts and known jump hosts can explain unusual activity.
Key takeaway
A good analyst does not ask only “Is this malicious?” They ask “What evidence supports or disproves each explanation?”