Anthropic Multiple Authentication Failures

Last updated 5 days ago on 2026-09-21
Created 14 days ago on 2026-09-12

About

Detects at least five failed Anthropic authentication events for the same user email within one hour. Failures are matched by authentication category and failure outcome (for example magic-link or SSO login failures). That pattern fits repeated guessing, stale magic link abuse, or automated login attempts against one account.
Tags
Domain: GenAIDomain: IdentityPlatform: AnthropicData Source: Anthropic Audit LogsUse Case: Identity and Access AuditUse Case: Threat DetectionUse Case: UEBARule Type: ES|QLTactic: Credential AccessLanguage: esql
Severity
medium
Risk Score
47
MITRE ATT&CK™

Credential Access (TA0006)(external, opens in a new tab or window)

False Positive Examples
A user repeatedly clicking an expired or invalid magic link from the same browser session can produce several failures before requesting a new link or signing in successfully. IdP or SSO cutover testing against a pilot account can generate a short burst of failed attempts for one email during maintenance windows.
License
Elastic License v2(external, opens in a new tab or window)

Definition

Integration Pack
Prebuilt Security Detection Rules
Related Integrations

anthropic(external, opens in a new tab or window)

Query
text code block:
from logs-anthropic.audit-* | where data_stream.dataset == "anthropic.audit" and mv_contains(event.category, "authentication") and event.outcome == "failure" and user.email is not null | stats Esql.event_count = count(*), Esql.event_id_values = values(event.id), Esql.event_action_values = values(event.action), Esql.source_ip_values = values(source.ip), Esql.source_ip_distinct_count = count_distinct(source.ip), Esql.user_agent_original_values = values(user_agent.original), Esql.anthropic_audit_actor_type_values = values(anthropic.audit.actor.type), Esql.timestamp_first_seen = min(@timestamp), Esql.timestamp_last_seen = max(@timestamp) by user.email | where Esql.event_count >= 5 | keep user.email, Esql.*

Install detection rules in Elastic Security

Detect Anthropic Multiple Authentication Failures in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(external, opens in a new tab or window).