One employee's failed sign-ins may look routine. The same period can look different when failures span many accounts and an unexpected application.
A useful defensive review asks what pattern the authorized identity records support, rather than focusing only on the noisiest individual account.
Understand the pattern you are investigating
MITRE describes password spraying as attempting a small set of passwords across multiple accounts. Investigators generally should not need the submitted passwords themselves to examine relevant authentication patterns.
Use supported identity-provider detections and logs. Establish which applications, accounts, times, source contexts, and outcomes are represented.
Do not assume a visible cluster proves a specific technique. A broken application, configuration change, or user workflow can produce failures that need a different response.
Build a compact timeline
For a hypothetical review, compare the start of a failure pattern with recent application changes, support reports, and any completed sign-ins requiring investigation.
| Dimension | Useful question |
|---|---|
| Accounts | Is the pattern isolated or spread across identities? |
| Applications | Does it affect one route or several services? |
| Time | Is the activity new relative to normal behavior? |
| Outcome | Were there successful sign-ins that need review? |
| Coverage | Which relevant routes are absent from these records? |
An IP address is context, not a person. Shared networks and changing connection paths make simplistic attribution unreliable.
Prioritize successful access separately
A large number of blocked attempts can be important, but it does not establish current unauthorized access. A smaller number of suspicious successful events may require a different urgency.
Correlate relevant activity through authorized identity and application owners. Check whether the account's authentication methods, recovery settings, or permissions changed.
Follow the organization's containment process when warranted. Avoid broad lockouts based only on an unexplained chart, especially where critical business or emergency accounts are involved.
Preserve visibility without collecting secrets
OWASP's logging guidance is a useful reference for sensitive fields and security events. Do not enable logging of submitted passwords to make an investigation easier.
Record the detection's coverage and limitations. If a local application route does not reach the central logs, treat that as a visibility gap rather than assuming it had no activity.
Read credential stuffing versus spraying and SSO's local-account boundaries. The investigation should end with an explained pattern and access decision, not merely a screenshot of failed sign-ins.