Netskope - Heavy Personal Cloud Storage Usage (Shadow IT)

Status: available
Severity: medium
Time window: 1h
Group by: CsUsername, XCCountry, XCDevice, XCsApp, XCsAppCategory, XCsAppInstanceName, XCsAppTags
Source: github.com/Azure/Azure-Sentinel

Detects heavy usage of personal cloud storage applications like personal Dropbox, Google Drive, OneDrive personal, etc. Indicates potential Shadow IT or data leakage risk.

MITRE ATT&CK coverage

Tactic	Techniques
Collection	`T1530` Data from Cloud Storage
Exfiltration	`T1567` Exfiltration Over Web Service

Rule body kusto

id: 272f9bca-5fd0-4413-b494-03b2d9f0bb9b
name: Netskope - Heavy Personal Cloud Storage Usage (Shadow IT)
description: |
  Detects heavy usage of personal cloud storage applications like personal Dropbox, Google Drive, OneDrive personal, etc. Indicates potential Shadow IT or data leakage risk.
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: NetskopeWebTxConnector
    dataTypes:
      - NetskopeWebTransactions_CL
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Exfiltration
  - Collection
relevantTechniques:
  - T1567
  - T1530
query: |
  let heavyUsageThresholdMB = 500;
  NetskopeWebTransactions_CL
  | where TimeGenerated > ago(1h)
  | where isnotempty(CsUsername) and isnotempty(XCsApp)
  | where XCsApp has_any ('Dropbox', 'Google Drive', 'OneDrive', 'Box', 'iCloud', 'pCloud', 'MEGA', 'MediaFire', 'WeTransfer')
  | where XCsAppInstanceTag contains 'Personal' 
      or XCsAppInstanceName contains 'Personal'
      or XCsAppTags contains 'Unsanctioned'
      or not(XCsAppTags contains 'Enterprise')
  | summarize 
      TotalBytes = sum(Bytes),
      UploadBytes = sum(CsBytes),
      DownloadBytes = sum(ScBytes),
      FileCount = dcount(XCsAppObjectName),
      Files = make_set(XCsAppObjectName, 10),
      Activities = make_set(XCsAppActivity),
      EventCount = count()
      by CsUsername, XCsApp, XCsAppCategory, XCsAppInstanceName, XCsAppTags, XCDevice, XCCountry
  | extend 
      TotalMB = round(TotalBytes / 1048576.0, 2),
      UploadMB = round(UploadBytes / 1048576.0, 2),
      DownloadMB = round(DownloadBytes / 1048576.0, 2)
  | where TotalMB > heavyUsageThresholdMB or FileCount > 50
  | project 
      TimeGenerated = now(),
      User = CsUsername,
      CloudApplication = XCsApp,
      AppCategory = XCsAppCategory,
      AppInstance = XCsAppInstanceName,
      AppTags = XCsAppTags,
      TotalDataMB = TotalMB,
      UploadMB,
      DownloadMB,
      FileCount,
      Files,
      Activities,
      Device = XCDevice,
      Country = XCCountry,
      EventCount
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: Name
        columnName: User
  - entityType: CloudApplication
    fieldMappings:
      - identifier: Name
        columnName: CloudApplication
version: 1.0.0
kind: Scheduled

Stages and Predicates

Parameters

let heavyUsageThresholdMB = 500;

Stage 1: `source`

NetskopeWebTransactions_CL

Stage 2: `where`

| where TimeGenerated > ago(1h)

Stage 3: `where`

| where isnotempty(CsUsername) and isnotempty(XCsApp)

Stage 4: `where`

| where XCsApp has_any ('Dropbox', 'Google Drive', 'OneDrive', 'Box', 'iCloud', 'pCloud', 'MEGA', 'MediaFire', 'WeTransfer')

Stage 5: `where`

| where XCsAppInstanceTag contains 'Personal' 
    or XCsAppInstanceName contains 'Personal'
    or XCsAppTags contains 'Unsanctioned'
    or not(XCsAppTags contains 'Enterprise')

Stage 6: `summarize`

| summarize 
    TotalBytes = sum(Bytes),
    UploadBytes = sum(CsBytes),
    DownloadBytes = sum(ScBytes),
    FileCount = dcount(XCsAppObjectName),
    Files = make_set(XCsAppObjectName, 10),
    Activities = make_set(XCsAppActivity),
    EventCount = count()
    by CsUsername, XCsApp, XCsAppCategory, XCsAppInstanceName, XCsAppTags, XCDevice, XCCountry

Stage 7: `extend`

| extend 
    TotalMB = round(TotalBytes / 1048576.0, 2),
    UploadMB = round(UploadBytes / 1048576.0, 2),
    DownloadMB = round(DownloadBytes / 1048576.0, 2)

Stage 8: `where`

| where TotalMB > heavyUsageThresholdMB or FileCount > 50

Stage 9: `project`

| project 
    TimeGenerated = now(),
    User = CsUsername,
    CloudApplication = XCsApp,
    AppCategory = XCsAppCategory,
    AppInstance = XCsAppInstanceName,
    AppTags = XCsAppTags,
    TotalDataMB = TotalMB,
    UploadMB,
    DownloadMB,
    FileCount,
    Files,
    Activities,
    Device = XCDevice,
    Country = XCCountry,
    EventCount

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
`CsUsername`	is_not_null	(no value, null check)
`FileCount`	gt	`50` transforms: `cased`
`TotalMB`	gt	`500` transforms: `cased`
`XCsApp`	is_not_null	(no value, null check)
`XCsApp`	match	`Box` `Dropbox` `Google Drive` `MEGA` `MediaFire` `OneDrive` `WeTransfer` `iCloud` `pCloud`
`XCsAppInstanceName`	contains	`Personal`
`XCsAppInstanceTag`	contains	`Personal`
`XCsAppTags`	contains	`Unsanctioned`

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
`Activities`	`project`
`AppCategory`	`project`
`AppInstance`	`project`
`AppTags`	`project`
`CloudApplication`	`project`
`Country`	`project`
`Device`	`project`
`DownloadMB`	`project`
`EventCount`	`project`
`FileCount`	`project`
`Files`	`project`
`TimeGenerated`	`project`
`TotalDataMB`	`project`
`UploadMB`	`project`
`User`	`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)

Netskope - Heavy Personal Cloud Storage Usage (Shadow IT)

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `where`

Stage 6: `summarize`

Stage 7: `extend`

Stage 8: `where`

Stage 9: `project`

Indicators

Output fields

Keyboard shortcuts

Search operators

Netskope - Heavy Personal Cloud Storage Usage (Shadow IT)

MITRE ATT&CK coverage

Rule body kusto

Stages and Predicates

Parameters

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: where

Stage 5: where

Stage 6: summarize

Stage 7: extend

Stage 8: where

Stage 9: project

Indicators

Output fields

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `where`

Stage 6: `summarize`

Stage 7: `extend`

Stage 8: `where`

Stage 9: `project`