Detection rules › Kusto
Azure DevOps New Extension Added
'Extensions add additional features to Azure DevOps. An attacker could use a malicious extension to conduct malicious activity. This query looks for new extensions that are not from a configurable list of approved publishers.'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1505 Server Software Component |
Rule body kusto
id: bf07ca9c-e408-443a-8939-6860a45a929e
name: Azure DevOps New Extension Added
description: |
'Extensions add additional features to Azure DevOps. An attacker could use a malicious extension to conduct malicious activity.
This query looks for new extensions that are not from a configurable list of approved publishers.'
severity: Low
status: Available
requiredDataConnectors: []
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
- Persistence
relevantTechniques:
- T1505
query: |
let allowed_publishers = dynamic([]);
ADOAuditLogs
| where OperationName =~ "Extension.Installed"
| extend ExtensionName = tostring(Data.ExtensionName)
| extend PublisherName = tostring(Data.PublisherName)
| where PublisherName !in (allowed_publishers)
| project-reorder TimeGenerated, OperationName, ExtensionName, PublisherName, ActorUPN, IpAddress, UserAgent, ScopeDisplayName, Data
| extend timestamp = TimeGenerated
| extend AccountName = tostring(split(ActorUPN, "@")[0]), AccountUPNSuffix = tostring(split(ActorUPN, "@")[1])
entityMappings:
- entityType: Account
fieldMappings:
- identifier: FullName
columnName: ActorUPN
- identifier: Name
columnName: AccountName
- identifier: UPNSuffix
columnName: AccountUPNSuffix
- entityType: IP
fieldMappings:
- identifier: Address
columnName: IpAddress
version: 1.0.4
kind: Scheduled
Stages and Predicates
Parameters
let allowed_publishers = dynamic([]);
Stage 1: source
ADOAuditLogs
Stage 2: where
| where OperationName =~ "Extension.Installed"
Stage 3: extend
| extend ExtensionName = tostring(Data.ExtensionName)
Stage 4: extend
| extend PublisherName = tostring(Data.PublisherName)
Stage 5: where
| where PublisherName !in (allowed_publishers)
Stage 6: project-reorder
| project-reorder TimeGenerated, OperationName, ExtensionName, PublisherName, ActorUPN, IpAddress, UserAgent, ScopeDisplayName, Data
Stage 7: extend
| extend timestamp = TimeGenerated
Stage 8: extend
| extend AccountName = tostring(split(ActorUPN, "@")[0]), AccountUPNSuffix = tostring(split(ActorUPN, "@")[1])
Exclusions
Top-level NOT(...) conjuncts: predicates this rule actively suppresses.
| Field | Kind | Excluded values |
|---|---|---|
PublisherName | eq | [] |
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 |
|---|---|---|
OperationName | eq |
|
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 |
|---|---|
ExtensionName | extend |
PublisherName | extend |
timestamp | extend |
AccountName | extend |
AccountUPNSuffix | extend |