XbowNewAssetDiscovered

Status: available
Severity: medium
Time window: 1h
Group by: AssetId
Source: github.com/Azure/Azure-Sentinel

Alerts when a new asset is registered in XBOW for the first time. This is detected by matching assets whose CreatedAt timestamp falls within the current query window, indicating the asset was newly added rather than updated. This helps track shadow IT, new deployments, and any unexpected expansion of the external attack surface.

MITRE ATT&CK coverage

Tactic	Techniques
Reconnaissance	`T1595` Active Scanning

Rule body kusto

id: e4c6a8b2-9d7f-4285-a1e3-6b9c2e4f1a85
name: XbowNewAssetDiscovered
description: |
  Alerts when a new asset is registered in XBOW for the first time. This is detected by
  matching assets whose CreatedAt timestamp falls within the current query window,
  indicating the asset was newly added rather than updated. This helps track shadow IT,
  new deployments, and any unexpected expansion of the external attack surface.
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: XbowSecurityConnector
    dataTypes:
      - XbowAssets_CL
queryFrequency: 30m
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Reconnaissance
  - Discovery
relevantTechniques:
  - T1595
query: |
  XbowAssets_CL
  | where TimeGenerated > ago(1h)
  // Only match assets created within the query window (new, not updated)
  | where todatetime(CreatedAt) > ago(1h)
  | summarize arg_max(TimeGenerated, *) by AssetId
  | project
      TimeGenerated,
      AssetId,
      AssetName,
      StartUrl,
      Lifecycle,
      Sku,
      OrganizationId,
      CreatedAt,
      UpdatedAt,
      AssetReachableState,
      AssetReachableMessage
eventGroupingSettings:
  aggregationKind: AlertPerResult
alertDetailsOverride:
  alertDisplayNameFormat: 'XBOW New Asset: {{AssetName}}'
  alertDescriptionFormat: 'New asset registered in XBOW: {{AssetName}} ({{StartUrl}}). Reachability: {{AssetReachableState}}'
customDetails:
  AssetID: AssetId
  AssetName: AssetName
  StartUrl: StartUrl
  Lifecycle: Lifecycle
  Sku: Sku
  OrganizationID: OrganizationId
  CreatedAt: CreatedAt
  AssetReachableState: AssetReachableState
incidentConfiguration:
  createIncident: true
  groupingConfiguration:
    enabled: true
    reopenClosedIncident: false
    lookbackDuration: 6h
    matchingMethod: Selected
    groupByCustomDetails:
      - AssetID
entityMappings:
  - entityType: URL
    fieldMappings:
      - identifier: Url
        columnName: StartUrl
version: 1.0.1
kind: Scheduled

Stages and Predicates

Stage 1: `source`

XbowAssets_CL

Stage 2: `where`

| where TimeGenerated > ago(1h)

Stage 3: `where`

| where todatetime(CreatedAt) > ago(1h)

Stage 4: `summarize`

| summarize arg_max(TimeGenerated, *) by AssetId

Stage 5: `project`

| project
    TimeGenerated,
    AssetId,
    AssetName,
    StartUrl,
    Lifecycle,
    Sku,
    OrganizationId,
    CreatedAt,
    UpdatedAt,
    AssetReachableState,
    AssetReachableMessage

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
`AssetId`	`project`
`AssetName`	`project`
`AssetReachableMessage`	`project`
`AssetReachableState`	`project`
`CreatedAt`	`project`
`Lifecycle`	`project`
`OrganizationId`	`project`
`Sku`	`project`
`StartUrl`	`project`
`TimeGenerated`	`project`
`UpdatedAt`	`project`

`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)

XbowNewAssetDiscovered

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `summarize`

Stage 5: `project`

Output fields

Keyboard shortcuts

Search operators

XbowNewAssetDiscovered

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: summarize

Stage 5: project

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `summarize`

Stage 5: `project`