Detection rules › Kusto
GitLab - External User Added to GitLab
'This queries GitLab Application logs to list external user accounts (i.e.: account not in allow-listed domains) which have been added to GitLab users.'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1136 Create Account |
Rule body kusto
id: c1544d8f-cbbd-4e35-8d32-5b9312279833
name: GitLab - External User Added to GitLab
description: |
'This queries GitLab Application logs to list external user accounts (i.e.: account not in allow-listed domains) which have been added to GitLab users.'
severity: Medium
status: Available
requiredDataConnectors:
- connectorId: SyslogAma
dataTypes:
- Syslog
queryFrequency: 1h
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
- Persistence
relevantTechniques:
- T1136
query: |
// List of allow-listed domains
let allowedDomain = pack_array("mydomain.com");
GitLabAudit
| where AddAction == "user"
| project AuthorName, IPAddress, User = EntityName
| join (GitLabApp
| where UserAdded == 1
| parse kind=regex Message with "User \"" User "\"" EmailAddress " was created"
| project tostring(User), EmailAddress = substring(EmailAddress,2,strlen(EmailAddress)-3)) on User
| project AuthorName, IPAddress, User, EmailAddress, DomainName = tostring(extract("@(.*)$", 1, EmailAddress))
| where allowedDomain !contains DomainName
entityMappings:
- entityType: IP
fieldMappings:
- identifier: Address
columnName: IPAddress
- entityType: Account
fieldMappings:
- identifier: FullName
columnName: User
- entityType: Account
fieldMappings:
- identifier: FullName
columnName: AuthorName
- entityType: DNS
fieldMappings:
- identifier: DomainName
columnName: DomainName
version: 1.0.1
kind: Scheduled
Stages and Predicates
Parameters
let allowedDomain = pack_array("mydomain.com");
Stage 1: source
GitLabAudit
Stage 2: where
| where AddAction == "user"
Stage 3: project
| project AuthorName, IPAddress, User = EntityName
Stage 4: join
| join (GitLabApp
| where UserAdded == 1
| parse kind=regex Message with "User \"" User "\"" EmailAddress " was created"
| project tostring(User), EmailAddress = substring(EmailAddress,2,strlen(EmailAddress)-3)) on User
Stage 5: project
| project AuthorName, IPAddress, User, EmailAddress, DomainName = tostring(extract("@(.*)$", 1, EmailAddress))
Stage 6: where
| where allowedDomain !contains DomainName
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
allowedDomain | contains | DomainName |
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.
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 |
|---|---|
AuthorName | project |
DomainName | project |
EmailAddress | project |
IPAddress | project |
User | project |