↳ GitHub sourceAnalytics ruleMedium
Potential Password Spray Attack (Uses Authentication Normalization)
Description
'This query searches for failed attempts to log in from more than 15 various users within a 5 minute timeframe from the same source. This is a potential indication of a password spray attack
To use this analytics rule, make sure you have deployed the [ASIM normalization parsers](https://aka.ms/ASimAuthentication)'
- Rule type
- Scheduled
- Version
- 1.1.3
- Query frequency
- 1h
- Query period
- 1h
- Trigger
- gt 0
Declared MITRE coverage
KQL query
Original query, unchanged.
let FailureThreshold = 15;
imAuthentication
| where EventType== 'Logon' and EventResult== 'Failure'
// reason: creds
| where EventResultDetails in ('No such user or password', 'Incorrect password')
| summarize UserCount=dcount(TargetUserId), Vendors=make_set(EventVendor), Products=make_set(EventVendor)
, Users = make_set(TargetUserId,100)
by SrcDvcIpAddr, SrcGeoCountry, bin(TimeGenerated, 5m)
| where UserCount > FailureThreshold
Declared entities
Source provenance
GitHubDisplayed values come from files in Azure/Azure-Sentinel. They describe the published template, not your workspace configuration.
- Commit
629d1d3↗- Source identifier
6a2e2ff4-5568-475e-bef2-b95f12b9367b
Additional source files 1
Detections/ASimAuthentication/imAuthPasswordSpray.yamlsource ↗GSTEP / CATALOG TRACKING
Added to catalog : 16 Sept 2026 · 05:49 UTC
Last change observed : 16 Sept 2026 · 05:49 UTC