Failed Logins from Unknown or Invalid User

Status: available
Severity: medium
Time window: 1h
Group by: City, ClientIP, Country, actor_alternateId_s
Source: github.com/Azure/Azure-Sentinel

This query searches for numerous login attempts to the management console with an unknown or invalid user name.

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1110` Brute Force

Event coverage

Provider	Event
Okta-user	user.session.start

Rules detecting the same action

Other rules on this platform that filter on the same API call or operation.

First Occurrence of Okta User Session Started via Proxy (Elastic)
High-Risk Admin Activity (Kusto)
Multiple Okta Sessions Detected for a Single User (Elastic)
Multiple Okta User Authentication Events with Same Device Token Hash (Elastic)
New Device/Location sign-in along with critical operation (Kusto)
Okta AiTM Session Cookie Replay (Elastic)
Okta Login Signal (Panther)
Okta Potentially Stolen Session (Panther)

Rule body kusto

id: 884be6e7-e568-418e-9c12-89229865ffde
name: Failed Logins from Unknown or Invalid User
description: |
  'This query searches for numerous login attempts to the management console with an unknown or invalid user name.'
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: OktaSSO
    dataTypes:
      - Okta_CL
  - connectorId: OktaSSOv2
    dataTypes:
      - OktaSSO
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CredentialAccess
relevantTechniques:
  - T1110
query: |
  let FailureThreshold = 15;
  let FailedLogins = OktaSSO
  | where eventType_s =~ "user.session.start" and outcome_reason_s =~ "VERIFICATION_ERROR"
  | summarize count() by actor_alternateId_s, client_ipAddress_s, bin(TimeGenerated, 5m)
  | where count_ > FailureThreshold
  | project client_ipAddress_s, actor_alternateId_s;
  OktaSSO
  | join kind=inner (FailedLogins) on client_ipAddress_s, actor_alternateId_s
  | where eventType_s =~ "user.session.start" and outcome_reason_s =~ "VERIFICATION_ERROR"
  | summarize count() by actor_alternateId_s, ClientIP = client_ipAddress_s, City = column_ifexists('client_geographicalContext_city_s', ""), Country = column_ifexists('client_geographicalContext_country_s', ""), column_ifexists('published_t', now())
  | sort by column_ifexists('published_t', now()) desc
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: actor_alternateId_s
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: ClientIP
version: 1.1.1
kind: Scheduled

Stages and Predicates

Parameters

let FailureThreshold = 15;

Let binding: `FailedLogins`

let FailedLogins = OktaSSO
| where eventType_s =~ "user.session.start" and outcome_reason_s =~ "VERIFICATION_ERROR"
| summarize count() by actor_alternateId_s, client_ipAddress_s, bin(TimeGenerated, 5m)
| where count_ > FailureThreshold
| project client_ipAddress_s, actor_alternateId_s;

Derived from FailureThreshold.

Stage 1: `source`

OktaSSO

Stage 2: `join`

| join kind=inner (FailedLogins) on client_ipAddress_s, actor_alternateId_s

Stage 3: `where`

| where eventType_s =~ "user.session.start" and outcome_reason_s =~ "VERIFICATION_ERROR"

Stage 4: `summarize`

| summarize count() by actor_alternateId_s, ClientIP = client_ipAddress_s, City = column_ifexists('client_geographicalContext_city_s', ""), Country = column_ifexists('client_geographicalContext_country_s', ""), column_ifexists('published_t', now())

Stage 5: `sort`

| sort by column_ifexists('published_t', now()) desc

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

Field	Kind	Values
`count_`	gt	`15` transforms: `cased`
`eventType_s`	eq	`user.session.start`
`outcome_reason_s`	eq	`VERIFICATION_ERROR`

Output fields

Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.

Field	Source
`City`	`summarize`
`ClientIP`	`summarize`
`Country`	`summarize`
`actor_alternateId_s`	`summarize`

`j` / `k`	Scroll down / up
`d` / `u`	Half-page down / up
`gg` / `G`	Top / bottom
`h` / `l`	History back / forward
`f`	Follow link (`Shift` = new tab)
`/`	Focus search
`?`	Toggle this help
`↑` / `↓`	Navigate search results
`Enter`	Open highlighted result
`Esc`	Close results / dialog

`type:`	`events` / `rules` / `providers`
`vendor:`	`sigma` / `elastic` / `splunk` / `kusto` / `chronicle` (vendor name alone also works: `sigma:`, `kql:`, `secops:`…)
`tactic:`	TA-id, slug, or name: `credential_access`, `TA0006`
`technique:`	technique or sub-technique ID: `T1003`, `T1003.001` (alias `tech:`)
`severity:`	`critical` / `high` / `medium` / `low` / `informational` (alias `sev:`)
`risk_score`	Numeric comparison on the Elastic risk score (0 to 100): `risk_score>50`, `risk_score<=20`, `risk_score=99` (alias `risk`; Elastic rules only)
`stages:`	Rules with exactly N pipeline stages
`correlation:`	`single_event` / `sequence` / `alternatives` / `alternatives_cross_log` / `all_required` / `correlated`
`with:`	Co-occurrence event-id; stacks (`with:4624 with:4769`) to require all, while a comma list in one occurrence (`with:4624,4769`) is an either-or group. Implies multi-event
`like:`	Structural neighbors of a rule slug (equivalents + subsumption stricter / broader): `like:comsvcs_lsass_memory_dump-splunk-sysmon`
`groupby:`	Entity-grouping substring match against `group_by_keys`: `groupby:user`, `groupby:host`
`uses:`	Rules whose predicate tree touches the field (any kind, any value): `uses:CommandLine`
`excludes:`	Rules with top-level `not()` clauses on the field (FP whitelists): `excludes:ParentImage`
`field:` / `value:`	Predicate search; narrows rule cards to those with a matching leaf and drives the indicator tier. Unquoted = substring, wildcards allowed (`value:mimikatz`)
`indicator:`	Shorthand for `field:F value:V`: `indicator:Image=*\powershell.exe`
`kind:`	Filter by predicate kind. Narrows rule cards to those carrying a matching predicate leaf (`vendor:elastic kind:cidr_match`) and drives the indicator tier: `contains` / `starts_with` / `ends_with` / `regex` / `cidr` / `eq` / `in` … (operator aliases `op:`/`match:`)
`has:` / `no:`	`sample`, `field`, `notes`, `refs`, `trace`, `thirdparty`, `rule`, `pattern`, `timewindow`, `threshold`, `newterms`, `sigma`/`elastic`/`splunk`/`kusto`/`chronicle`
`-op:val`	Exclude matches; works on most operators but not `type:`/`like:`/`has:`/`no:` (use `no:<flag>` to exclude a rule flag): `tactic:execution -vendor:splunk`. Standalone `-kind:`/`-field:`/`-value:` drop every rule carrying a matching predicate leaf (`type:rules -kind:is_null`)
`field:"…"` / `value:"…"`	Quoted value = anchored exact match (also allows spaces): `value:"net user"`
`a,b`	Comma = OR inside one operator (`vendor:sigma,elastic`, `severity:high,critical`); repeating a facet merges the same way. `field:`/`value:` never split (literal commas)
`vendors:` / `stage:`	Singular and plural spellings fold to the canonical operator and value: `tactics:` = `tactic:`, `type:event` = `type:events`, `correlation:sequences` = `correlation:sequence`, `has:thresholds` = `has:threshold`
`"quoted phrase"`	Exact-match a multi-word phrase (free text)

Failed Logins from Unknown or Invalid User

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Parameters

Let binding: `FailedLogins`

Stage 1: `source`

Stage 2: `join`

Stage 3: `where`

Stage 4: `summarize`

Stage 5: `sort`

Indicators

Output fields

Keyboard shortcuts

Search operators

Failed Logins from Unknown or Invalid User

MITRE ATT&CK coverage

Event coverage

Rules detecting the same action

Rule body kusto

Stages and Predicates

Parameters

Let binding: FailedLogins

Stage 1: source

Stage 2: join

Stage 3: where

Stage 4: summarize

Stage 5: sort

Indicators

Output fields

Let binding: `FailedLogins`

Stage 1: `source`

Stage 2: `join`

Stage 3: `where`

Stage 4: `summarize`

Stage 5: `sort`