Azure DevOps Service Connection Addition/Abuse - Historic allow list

Status: available
Severity: medium
Time window: 14d
Group by: ActorUPN, DefId, OrganizationName, ProjectId, ProjectName, Type
Source: github.com/Azure/Azure-Sentinel

'This detection builds an allow list of historic service connection use by Builds and Releases and compares to recent history, flagging growth of service connection use which are not manually included in the allow list and not historically included in the allow list Build/Release runs. This is to determine if someone is hijacking a build/release and adding many service connections in order to abuse or dump credentials from service connections.'

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1098` Account Manipulation
Impact	`T1496` Resource Hijacking

Rule body kusto

id: 5efb0cfd-063d-417a-803b-562eae5b0301
name: Azure DevOps Service Connection Addition/Abuse - Historic allow list
description: |
  'This detection builds an allow list of historic service connection use by Builds and Releases and compares to recent history, flagging growth of service connection use which are not manually included in the allow list and not historically included in the allow list Build/Release runs.
  This is to determine if someone is hijacking a build/release and adding many service connections in order to abuse or dump credentials from service connections.'
severity: Medium
status: Available
requiredDataConnectors: []
queryFrequency: 6h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Persistence
  - Impact
relevantTechniques:
  - T1098
  - T1496
query: |
  let starttime = 14d;
  let endtime = 6h;
  // Ignore Build/Releases with less/equal this number
  let ServiceConnectionThreshold = 3;
  // New Connections need to exhibit execution of more "new" connections than this number.
  let NewConnectionThreshold = 1;
  // List of Builds/Releases to ignore in your space
  let BypassDefIds = datatable(DefId:string, Type:string, ProjectName:string)
  [
  //"103", "Release", "ProjectA",
  //"42", "Release", "ProjectB",
  //"122", "Build", "ProjectB"
  ];
  let HistoricDefs = ADOAuditLogs
  | where TimeGenerated between (ago(starttime) .. ago(endtime))
  | where OperationName == "Library.ServiceConnectionExecuted"
  | extend DefId = tostring(Data.DefinitionId), Type = tostring(Data.PlanType), ConnectionId = tostring(Data.ConnectionId)
  | summarize HistoricCount = dcount(tostring(ConnectionId)), ConnectionNames = make_set(tostring(Data.ConnectionName))
    by DefId = tostring(DefId), Type = tostring(Type), ProjectId, ProjectName, ActorUPN;
  ADOAuditLogs
  | where TimeGenerated >= ago(endtime)
  | where OperationName == "Library.ServiceConnectionExecuted"
  | extend DefId = tostring(Data.DefinitionId), Type = tostring(Data.PlanType), ConnectionId = tostring(Data.ConnectionId)
  | parse ScopeDisplayName with OrganizationName ' (Organization)'
  | summarize CurrentCount = dcount(tostring(ConnectionId)), ConnectionNames = make_set(tostring(Data.ConnectionName)), StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)
    by OrganizationName, DefId = tostring(DefId), Type = tostring(Type), ProjectId, ProjectName, ActorUPN
  | where CurrentCount > ServiceConnectionThreshold
  | join (HistoricDefs) on ProjectId, DefId, Type, ActorUPN
  | join kind=anti BypassDefIds on $left.DefId==$right.DefId and $left.Type == $right.Type and $left.ProjectName == $right.ProjectName
  | extend link = iff(
  Type == "Build", strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_build?definitionId=', DefId),
  strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_release?_a=releases&view=mine&definitionId=', DefId))
  | where CurrentCount >= HistoricCount + NewConnectionThreshold
  | project StartTime, OrganizationName, ProjectName, DefId, link, RecentDistinctServiceConnections = CurrentCount, HistoricDistinctServiceConnections = HistoricCount,
    RecentConnections = ConnectionNames, HistoricConnections = ConnectionNames1, ActorUPN
  | extend timestamp = StartTime
  | 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
version: 1.0.6
kind: Scheduled

Stages and Predicates

Parameters

let starttime = 14d;
let endtime = 6h;
let ServiceConnectionThreshold = 3;
let NewConnectionThreshold = 1;

Let binding: `BypassDefIds`

let BypassDefIds = datatable(DefId:string, Type:string, ProjectName:string)
[
];

Let binding: `HistoricDefs`

let HistoricDefs = ADOAuditLogs
| where TimeGenerated between (ago(starttime) .. ago(endtime))
| where OperationName == "Library.ServiceConnectionExecuted"
| extend DefId = tostring(Data.DefinitionId), Type = tostring(Data.PlanType), ConnectionId = tostring(Data.ConnectionId)
| summarize HistoricCount = dcount(tostring(ConnectionId)), ConnectionNames = make_set(tostring(Data.ConnectionName))
  by DefId = tostring(DefId), Type = tostring(Type), ProjectId, ProjectName, ActorUPN;

Derived from starttime, endtime.

Stage 1: `source`

ADOAuditLogs

Stage 2: `where`

| where TimeGenerated >= ago(endtime)

Stage 3: `where`

| where OperationName == "Library.ServiceConnectionExecuted"

Stage 4: `extend`

| extend DefId = tostring(Data.DefinitionId), Type = tostring(Data.PlanType), ConnectionId = tostring(Data.ConnectionId)

Stage 5: `parse`

| parse ScopeDisplayName with OrganizationName ' (Organization)'

Stage 6: `summarize`

| summarize CurrentCount = dcount(tostring(ConnectionId)), ConnectionNames = make_set(tostring(Data.ConnectionName)), StartTime = min(TimeGenerated), EndTime = max(TimeGenerated)
  by OrganizationName, DefId = tostring(DefId), Type = tostring(Type), ProjectId, ProjectName, ActorUPN

Threshold: gt 3

Stage 7: `where`

| where CurrentCount > ServiceConnectionThreshold

Stage 8: `join`

| join (HistoricDefs) on ProjectId, DefId, Type, ActorUPN

Stage 9: `join` (negated)

| join kind=anti BypassDefIds on $left.DefId==$right.DefId and $left.Type == $right.Type and $left.ProjectName == $right.ProjectName

Stage 10: `extend`

| extend link = iff(
Type == "Build", strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_build?definitionId=', DefId),
strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_release?_a=releases&view=mine&definitionId=', DefId))

link =

ifType == "Build"strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_build?definitionId=', DefId)

else

strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_release?_a=releases&view=mine&definitionId=', DefId)

Stage 11: `where`

| where CurrentCount >= HistoricCount + NewConnectionThreshold

Stage 12: `project`

| project StartTime, OrganizationName, ProjectName, DefId, link, RecentDistinctServiceConnections = CurrentCount, HistoricDistinctServiceConnections = HistoricCount,
  RecentConnections = ConnectionNames, HistoricConnections = ConnectionNames1, ActorUPN

Stage 13: `extend`

| extend timestamp = StartTime

Stage 14: `extend`

| extend AccountName = tostring(split(ActorUPN, "@")[0]), AccountUPNSuffix = tostring(split(ActorUPN, "@")[1])

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
`CurrentCount`	gt	`3` transforms: `cased`
`OperationName`	eq	`Library.ServiceConnectionExecuted` transforms: `cased`

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
`ActorUPN`	`project`
`DefId`	`project`
`HistoricConnections`	`project`
`HistoricDistinctServiceConnections`	`project`
`OrganizationName`	`project`
`ProjectName`	`project`
`RecentConnections`	`project`
`RecentDistinctServiceConnections`	`project`
`StartTime`	`project`
`link`	`project`
`timestamp`	`extend`
`AccountName`	`extend`
`AccountUPNSuffix`	`extend`

`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)

Azure DevOps Service Connection Addition/Abuse - Historic allow list

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: `BypassDefIds`

Let binding: `HistoricDefs`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `extend`

Stage 5: `parse`

Stage 6: `summarize`

Stage 7: `where`

Stage 8: `join`

Stage 9: `join` (negated)

Stage 10: `extend`

Stage 11: `where`

Stage 12: `project`

Stage 13: `extend`

Stage 14: `extend`

Indicators

Output fields

Keyboard shortcuts

Search operators

Azure DevOps Service Connection Addition/Abuse - Historic allow list

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: BypassDefIds

Let binding: HistoricDefs

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: extend

Stage 5: parse

Stage 6: summarize

Stage 7: where

Stage 8: join

Stage 9: join (negated)

Stage 10: extend

Stage 11: where

Stage 12: project

Stage 13: extend

Stage 14: extend

Indicators

Output fields

Let binding: `BypassDefIds`

Let binding: `HistoricDefs`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `extend`

Stage 5: `parse`

Stage 6: `summarize`

Stage 7: `where`

Stage 8: `join`

Stage 9: `join` (negated)

Stage 10: `extend`

Stage 11: `where`

Stage 12: `project`

Stage 13: `extend`

Stage 14: `extend`