Azure DevOps Variable Secret Not Secured

Status: available
Severity: medium
Time window: 1d
Source: github.com/Azure/Azure-Sentinel

'Credentials used in the build process may be stored as Azure DevOps variables. To secure these variables they should be stored in KeyVault or marked as Secrets. This detection looks for new variables added with names that suggest they are credentials but where they are not set as Secrets or stored in KeyVault.'

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1552` Unsecured Credentials

Rule body kusto

id: 4ca74dc0-8352-4ac5-893c-73571cc78331
name: Azure DevOps Variable Secret Not Secured
description: |
  'Credentials used in the build process may be stored as Azure DevOps variables. To secure these variables they should be stored in KeyVault or marked as Secrets. 
  This detection looks for new variables added with names that suggest they are credentials but where they are not set as Secrets or stored in KeyVault.'
severity: Medium
status: Available
requiredDataConnectors: []
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - CredentialAccess
relevantTechniques:
  - T1552
query: |
  let keywords = dynamic(["secret", "secrets", "password", "PAT", "passwd", "pswd", "pwd", "cred", "creds", "credentials", "credential", "key"]);
  ADOAuditLogs
  | where OperationName =~ "Library.VariableGroupModified"
  | extend Type = tostring(Data.Type)
  | extend VariableGroupId = tostring(Data.VariableGroupId)
  | extend VariableGroupName = tostring(Data.VariableGroupName)
  | mv-expand Data.Variables
  | where VariableGroupName has_any (keywords) or Data_Variables has_any (keywords)
  | where Type != "AzureKeyVault"
  | where Data_Variables !has "IsSecret"
  | 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 keywords = dynamic(["secret", "secrets", "password", "PAT", "passwd", "pswd", "pwd", "cred", "creds", "credentials", "credential", "key"]);

Stage 1: `source`

ADOAuditLogs

Stage 2: `where`

| where OperationName =~ "Library.VariableGroupModified"

Stage 3: `extend` (3 consecutive steps)

| extend Type = tostring(Data.Type)
| extend VariableGroupId = tostring(Data.VariableGroupId)
| extend VariableGroupName = tostring(Data.VariableGroupName)

Stage 4: `mv-expand`

| mv-expand Data.Variables

Stage 5: `where`

| where VariableGroupName has_any (keywords) or Data_Variables has_any (keywords)

Stage 6: `where`

| where Type != "AzureKeyVault"

Stage 7: `where`

| where Data_Variables !has "IsSecret"

Stage 8: `extend`

| extend timestamp = TimeGenerated

Stage 9: `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
`Data_Variables`	match	`IsSecret`

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
`Data_Variables`	match	`PAT` `cred` `credential` `credentials` `creds` `key` `passwd` `password` `pswd` `pwd` `secret` `secrets`
`OperationName`	eq	`Library.VariableGroupModified`
`Type`	ne	`AzureKeyVault` transforms: `cased`
`VariableGroupName`	match	`PAT` `cred` `credential` `credentials` `creds` `key` `passwd` `password` `pswd` `pwd` `secret` `secrets`

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
`Type`	`extend`
`VariableGroupId`	`extend`
`VariableGroupName`	`extend`
`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 Variable Secret Not Secured

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend` (3 consecutive steps)

Stage 4: `mv-expand`

Stage 5: `where`

Stage 6: `where`

Stage 7: `where`

Stage 8: `extend`

Stage 9: `extend`

Exclusions

Indicators

Output fields

Keyboard shortcuts

Search operators

Azure DevOps Variable Secret Not Secured

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: source

Stage 2: where

Stage 3: extend (3 consecutive steps)

Stage 4: mv-expand

Stage 5: where

Stage 6: where

Stage 7: where

Stage 8: extend

Stage 9: extend

Exclusions

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `extend` (3 consecutive steps)

Stage 4: `mv-expand`

Stage 5: `where`

Stage 6: `where`

Stage 7: `where`

Stage 8: `extend`

Stage 9: `extend`