Azure DevOps Pull Request Policy Bypassing - Historic allow list

Status: available
Severity: medium
Time window: 14d
Source: github.com/Azure/Azure-Sentinel

'This detection builds an allow list of historic PR policy bypasses and compares to recent history, flagging pull request bypasses that are not manually in the allow list and not historically included in the allow list.'

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1098` Account Manipulation

Rule body kusto

id: 4d8de9e6-263e-4845-8618-cd23a4f58b70
name: Azure DevOps Pull Request Policy Bypassing - Historic allow list
description: |
  'This detection builds an allow list of historic PR policy bypasses and compares to recent history, flagging pull request bypasses that are not manually in the allow list and not historically included in the allow list.'
severity: Medium
status: Available
requiredDataConnectors: []
queryFrequency: 3h
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Persistence
relevantTechniques:
  - T1098
query: |
  let starttime = 14d;
  let endtime = 3h;
  // Add full UPN (user@domain.com) to Authorized Bypassers to ignore policy bypasses by certain authorized users
  let AuthorizedBypassers = dynamic(['foo@baz.com', 'test@foo.com']);
  let historicBypassers = ADOAuditLogs
  | where TimeGenerated between (ago(starttime) .. ago(endtime))
  | where OperationName == 'Git.RefUpdatePoliciesBypassed'
  | distinct ActorUPN;
  ADOAuditLogs
  | where TimeGenerated >= ago(endtime)
  | where OperationName == 'Git.RefUpdatePoliciesBypassed'
  | where ActorUPN !in (historicBypassers) and ActorUPN !in (AuthorizedBypassers)
  | parse ScopeDisplayName with OrganizationName '(Organization)'
  | project TimeGenerated, ActorUPN, IpAddress, UserAgent, OrganizationName, ProjectName, RepoName = Data.RepoName, AlertDetails = Details, Branch = Data.Name,
    BypassReason = Data.BypassReason, PRLink = strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_git/', Data.RepoName, '/pullrequest/', Data.PullRequestId)
  | 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
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: PRLink
version: 1.0.6
kind: Scheduled

Stages and Predicates

Parameters

let starttime = 14d;
let endtime = 3h;
let AuthorizedBypassers = dynamic(['foo@baz.com', 'test@foo.com']);

Let binding: `historicBypassers`

let historicBypassers = ADOAuditLogs
| where TimeGenerated between (ago(starttime) .. ago(endtime))
| where OperationName == 'Git.RefUpdatePoliciesBypassed'
| distinct ActorUPN;

Derived from starttime, endtime.

Stage 1: `source`

ADOAuditLogs

Stage 2: `where`

| where TimeGenerated >= ago(endtime)

Stage 3: `where`

| where OperationName == 'Git.RefUpdatePoliciesBypassed'

Stage 4: `where`

| where ActorUPN !in (historicBypassers) and ActorUPN !in (AuthorizedBypassers)

References historicBypassers (defined above).

Stage 5: `parse`

| parse ScopeDisplayName with OrganizationName '(Organization)'

Stage 6: `project`

| project TimeGenerated, ActorUPN, IpAddress, UserAgent, OrganizationName, ProjectName, RepoName = Data.RepoName, AlertDetails = Details, Branch = Data.Name,
  BypassReason = Data.BypassReason, PRLink = strcat('https://dev.azure.com/', OrganizationName, '/', ProjectName, '/_git/', Data.RepoName, '/pullrequest/', Data.PullRequestId)

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
`ActorUPN`	eq	`historicBypassers`
`ActorUPN`	in	`foo@baz.com`, `test@foo.com`

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	`Git.RefUpdatePoliciesBypassed` 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`
`AlertDetails`	`project`
`Branch`	`project`
`BypassReason`	`project`
`IpAddress`	`project`
`OrganizationName`	`project`
`PRLink`	`project`
`ProjectName`	`project`
`RepoName`	`project`
`TimeGenerated`	`project`
`UserAgent`	`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 Pull Request Policy Bypassing - Historic allow list

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: `historicBypassers`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `parse`

Stage 6: `project`

Stage 7: `extend`

Stage 8: `extend`

Exclusions

Indicators

Output fields

Keyboard shortcuts

Search operators

Azure DevOps Pull Request Policy Bypassing - Historic allow list

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: historicBypassers

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: where

Stage 5: parse

Stage 6: project

Stage 7: extend

Stage 8: extend

Exclusions

Indicators

Output fields

Let binding: `historicBypassers`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `parse`

Stage 6: `project`

Stage 7: `extend`

Stage 8: `extend`