Threat Essentials - Mass Cloud resource deletions Time Series Anomaly

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

'This query generates baseline pattern of cloud resource deletions by an user and generated anomaly when any unusual spike is detected. These anomalies from unusual or privileged users could be an indication of cloud infrastructure take-down by an adversary '

MITRE ATT&CK coverage

Tactic	Techniques
Impact	`T1485` Data Destruction

Rule body kusto

id: fa2658fe-3714-4c55-bb12-2b7275c628e8
name: Threat Essentials - Mass Cloud resource deletions Time Series Anomaly
description: |
  'This query generates baseline pattern of cloud resource deletions by an user and generated anomaly when any unusual spike is detected.
  These anomalies from unusual or privileged users could be an indication of cloud infrastructure take-down by an adversary '
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: AzureActivity
    dataTypes:
      - AzureActivity
queryFrequency: 1d
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Impact
relevantTechniques:
  - T1485
tags:
  - DEV-0537
query: |
  let starttime = 14d;
  let endtime = 1d;
  let timeframe = 1h;
  let TotalEventsThreshold = 25; 
  let TimeSeriesData = 
  AzureActivity 
  | where TimeGenerated between (startofday(ago(starttime))..startofday(ago(endtime)))
  | where OperationNameValue endswith "delete" 
  | project TimeGenerated, Caller 
  | make-series Total = count() on TimeGenerated from startofday(ago(starttime)) to startofday(ago(endtime)) step timeframe by Caller; 
  let TimeSeriesAlerts = materialize(TimeSeriesData 
  | extend (anomalies, score, baseline) = series_decompose_anomalies(Total, 3, -1, 'linefit') 
  | mv-expand Total to typeof(double), TimeGenerated to typeof(datetime), anomalies to typeof(double), score to typeof(double), baseline to typeof(long) 
  | where anomalies > 0 
  | project Caller, TimeGenerated, Total, baseline, anomalies, score 
  | where Total > TotalEventsThreshold and baseline > 0 ); 
  TimeSeriesAlerts 
  | where TimeGenerated > (ago(endtime)) 
  | project TimeGenerated, Caller 
  | join kind = inner (AzureActivity 
  | where TimeGenerated > (ago(endtime)) 
  | where OperationNameValue endswith "delete" 
  | summarize count(), make_set(OperationNameValue), make_set(Resource) by bin(TimeGenerated, 1h), Caller) on TimeGenerated, Caller 
  | extend Name = iif(Caller has '@',tostring(split(Caller,'@',0)[0]),"")
  | extend UPNSuffix = iif(Caller has '@',tostring(split(Caller,'@',1)[0]),"")
  | extend AadUserId = iif(Caller !has '@',Caller,"")
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: Name
      - identifier: UPNSuffix
        columnName: UPNSuffix
      - identifier: AadUserId
        columnName: AadUserId
version: 1.0.2
kind: Scheduled

Stages and Predicates

Parameters

let starttime = 14d;
let endtime = 1d;
let timeframe = 1h;
let TotalEventsThreshold = 25;

The stages below define let TimeSeriesAlerts (the rule's main pipeline source).

Stage 1: `source`

TimeSeriesData

Stage 2: `extend`

extend anomalies, baseline, score

Stage 3: `mv-expand`

mv-expand Total

Stage 4: `where`

where anomalies > 0

Stage 5: `project`

project Caller, TimeGenerated, Total, anomalies, baseline, score

Stage 6: `where`

where Total > 25 and baseline > 0

Stage 7: `where`

where ...

Stage 8: `project`

project Caller, TimeGenerated

Stage 9: `join`

join kind=inner (...)

Stage 10: `extend` (3 consecutive steps)

extend Name

Stage 11: `summarize`

summarize by Caller

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
`OperationNameValue`	ends_with	`delete`
`Total`	gt	`25` transforms: `cased`
`anomalies`	gt	`0` transforms: `cased`
`baseline`	gt	`0` 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
`Caller`	`summarize`

`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)

Threat Essentials - Mass Cloud resource deletions Time Series Anomaly

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: `source`

Stage 2: `extend`

Stage 3: `mv-expand`

Stage 4: `where`

Stage 5: `project`

Stage 6: `where`

Stage 7: `where`

Stage 8: `project`

Stage 9: `join`

Stage 10: `extend` (3 consecutive steps)

Stage 11: `summarize`

Indicators

Output fields

Keyboard shortcuts

Search operators

Threat Essentials - Mass Cloud resource deletions Time Series Anomaly

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: source

Stage 2: extend

Stage 3: mv-expand

Stage 4: where

Stage 5: project

Stage 6: where

Stage 7: where

Stage 8: project

Stage 9: join

Stage 10: extend (3 consecutive steps)

Stage 11: summarize

Indicators

Output fields

Stage 1: `source`

Stage 2: `extend`

Stage 3: `mv-expand`

Stage 4: `where`

Stage 5: `project`

Stage 6: `where`

Stage 7: `where`

Stage 8: `project`

Stage 9: `join`

Stage 10: `extend` (3 consecutive steps)

Stage 11: `summarize`