Detection rules › Kusto Query Language

Brute force attack against user credentials (Uses Authentication Normalization)

Author
Ofer Shezaf
Source
upstream

'Identifies evidence of brute force activity against a user based on multiple authentication failures and at least one successful authentication within a given time window. Note that the query does not enforce any sequence, and does not require the successful authentication to occur last. The default failure threshold is 10, success threshold is 1, and the default time window is 20 minutes. To use this analytics rule, make sure you have deployed the ASIM normalization parsers'

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1110 Brute Force

Event coverage

ProviderEvent IDTitle
Security-Auditing4624An account was successfully logged on.
Security-Auditing4625An account failed to log on.
Security-Auditing4634An account was logged off.

Stages and Predicates

Stage 1: source

imAuthentication

Stage 2: where

TargetUserType ne "NonInteractive"

Stage 3: summarize

Stage 4: where

and
  FailureCount ge "failureCountThreshold"
  SuccessCount ge "successCountThreshold"

Stage 5: extend

Stage 6: extend

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.

FieldKindValues
FailureCountge
  • failureCountThreshold
SuccessCountge
  • successCountThreshold
TargetUserTypene
  • NonInteractive