Google Workspace Application Access Level Modified

Status: test
Severity: medium
Log source: product gcp, service google_workspace.admin
Author: Bryan Lim
Source: github.com/SigmaHQ/sigma

Detects when an access level is changed for a Google workspace application. An access level is part of BeyondCorp Enterprise which is Google Workspace's way of enforcing Zero Trust model. An adversary would be able to remove access levels to gain easier access to Google workspace resources.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1098.003` Account Manipulation: Additional Cloud Roles
Privilege Escalation	`T1098.003` Account Manipulation: Additional Cloud Roles

Event coverage

Provider	Event	Title
GoogleWorkspace-admin	CHANGE_APPLICATION_SETTING	Change Application Setting

Rule body yaml

title: Google Workspace Application Access Level Modified
id: 22f2fb54-5312-435d-852f-7c74f81684ca
status: test
description: |
    Detects when an access level is changed for a Google workspace application.
    An access level is part of BeyondCorp Enterprise which is Google Workspace's way of enforcing Zero Trust model.
    An adversary would be able to remove access levels to gain easier access to Google workspace resources.
references:
    - https://developers.google.com/admin-sdk/reports/v1/appendix/activity/admin-application-settings
    - https://support.google.com/a/answer/9261439
author: Bryan Lim
date: 2024-01-12
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.t1098.003
logsource:
    product: gcp
    service: google_workspace.admin
detection:
    selection:
        eventService: 'admin.googleapis.com'
        eventName: 'CHANGE_APPLICATION_SETTING'
        setting_name|startswith: 'ContextAwareAccess'
    condition: selection
falsepositives:
    - Legitimate administrative activities changing the access levels for an application
level: medium

Stages and Predicates

Stage 0: `condition`

selection

Stage 1: `selection`

selection:
    eventService: 'admin.googleapis.com'
    eventName: 'CHANGE_APPLICATION_SETTING'
    setting_name|startswith: 'ContextAwareAccess'

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
`eventName`	eq	`CHANGE_APPLICATION_SETTING`
`eventService`	eq	`admin.googleapis.com`
`setting_name`	starts_with	`ContextAwareAccess`

`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)

Google Workspace Application Access Level Modified

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: `condition`

Stage 1: `selection`

Indicators

Keyboard shortcuts

Search operators

Google Workspace Application Access Level Modified

MITRE ATT&CK coverage

Event coverage

Rule body yaml

Stages and Predicates

Stage 0: condition

Stage 1: selection

Indicators

Stage 0: `condition`

Stage 1: `selection`