Distributed Password Spraying via Authentication Failures Across Multiple Accounts

Technique Detected:  Password Spraying | T1110.003

ID: DET0487
Domains: Enterprise
Analytics: AN1336, AN1337, AN1338, AN1339, AN1340, AN1341, AN1342, AN1343
Version: 1.0
Created: 21 October 2025
Last Modified: 21 October 2025

Analytics

AN1336

A high volume of authentication failures using a single password (or small set) across many different user accounts within a defined time window

Log Sources
Data Component Name Channel
User Account Authentication (DC0002) WinEventLog:Security EventCode=4625, 4771, 4648
Mutable Elements
Field Description
PasswordReuseThreshold Number of distinct accounts a password is used against before alerting
TimeWindow Window over which the correlation is measured (e.g., 10 mins)
TargetGroupFilter Limit detection to sensitive or monitored user groups (e.g., Admins)

AN1337

Authentication failures across different accounts using a repeated or similar password via SSH or PAM stack within a short window

Log Sources
Data Component Name Channel
User Account Authentication (DC0002) linux:syslog Failed password for invalid user
Mutable Elements
Field Description
PasswordReusePattern Repetition or minor variation of the same password across user attempts
IPAggregationWindow Length of time to observe distributed spray attempts from single source

AN1338

Multiple failed login attempts across different users using common password patterns (e.g., 'Welcome2023')

Log Sources
Data Component Name Channel
User Account Authentication (DC0002) macos:unifiedlog Login Window and Authd errors
Mutable Elements
Field Description
RetryCountThreshold Total number of attempts before alerting
CommonPasswordList List of passwords considered suspicious due to widespread use

AN1339

Sign-in failures across enterprise SSO applications or SaaS platforms from same IP address using the same password against multiple user identities

Log Sources
Data Component Name Channel
User Account Authentication (DC0002) azure:signinlogs Failure Reason + UserPrincipalName
Mutable Elements
Field Description
GeoIPAnomalyCheck Use geolocation mismatches to strengthen signal
FailedUserRatio Proportion of total user base affected to filter noise

AN1340

Authentication failure logs on routers/switches showing repeated use of default or common passwords across multiple accounts

Log Sources
Data Component Name Channel
User Account Authentication (DC0002) networkdevice:syslog AAA or TACACS authentication failures
Mutable Elements
Field Description
AuthFailureBurst Cluster of failed attempts in short period indicating spray
InterfaceFilter Limit detection to console/SSH vs web UI interfaces

AN1341

Repeated failed authentication attempts to container APIs, control planes, or login shells across many user names using same password

Log Sources
Data Component Name Channel
User Account Authentication (DC0002) kubernetes:audit Failed login
Mutable Elements
Field Description
OrchestrationScope Detect spray attempts scoped to single pod vs full cluster
ServiceAccountFilter Limit detection to non-service accounts to reduce noise

AN1342

Failed authentication attempts across user mailboxes using identical or common passwords (e.g., OWA brute attempts)

Log Sources
Data Component Name Channel
User Account Authentication (DC0002) m365:exchange FailedLogin
Mutable Elements
Field Description
MailboxAccessAttempts Threshold on mailbox login failures by same IP
EmailPatternAnalysis Match target usernames to common spray dictionaries

AN1343

SaaS applications receiving authentication failures for dozens of accounts using same password or login signature

Log Sources
Data Component Name Channel
User Account Authentication (DC0002) saas:auth signin_failed
Mutable Elements
Field Description
CloudAppScope Restrict detection to identity providers or select high-risk SaaS platforms
UserPopulationSensitivity Adjust based on size and role of account pool