---
title: 'OSSEC Alert: Unusual spike in authentication failure'
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: >-
  Docs > Datadog Security > OOTB Rules > OSSEC Alert: Unusual spike in
  authentication failure
---

# OSSEC Alert: Unusual spike in authentication failure

{% alert level="danger" %}
This rule is part of a beta feature. To learn more, [contact Support](https://docs.datadoghq.com/help/).
{% /alert %}
Classification:attackTactic:[TA0006-credential-access](https://attack.mitre.org/tactics/TA0006)Technique:[T1110-brute-force](https://attack.mitre.org/techniques/T1110) 
## Goal{% #goal %}

Detect when there are a higher number of failed authentication attempts than usual.

## Strategy{% #strategy %}

This rule monitors logs for unusual spikes in failed authentication attempts using the anomaly detection method.

## Triage and Response{% #triage-and-response %}

1. Analyze the source and username which have generated the most authentication failure alerts.
1. Contact the system administrator to take necessary steps by changing the password of the user which has been affected or blocking the source IP from which failed authentication alerts have been generated.