Account added and removed from privileged groups

Severity: low
Time window: 1d
Group by: AccountAdded_GroupAddedTo_AddingAccount, AccountRemoved_GroupRemovedFrom_RemovingAccount
Author: Microsoft Security Research
Source: github.com/Azure/Azure-Sentinel

Identifies accounts that are added to a privileged group and then quickly removed, which could be a sign of compromise.

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1078` Valid Accounts, `T1098` Account Manipulation
Privilege Escalation	`T1078` Valid Accounts, `T1098` Account Manipulation

Event coverage

Provider	Event	Title
Security-Auditing	Event ID 4728	A member was added to a security-enabled global group.
Security-Auditing	Event ID 4729	A member was removed from a security-enabled global group.
Security-Auditing	Event ID 4732	A member was added to a security-enabled local group.
Security-Auditing	Event ID 4733	A member was removed from a security-enabled local group.
Security-Auditing	Event ID 4756	A member was added to a security-enabled universal group.
Security-Auditing	Event ID 4757	A member was removed from a security-enabled universal group.

Rule body kusto

id: 7efc75ce-e2a4-400f-a8b1-283d3b0f2c60
name: Account added and removed from privileged groups
description: |
  'Identifies accounts that are added to a privileged group and then quickly removed, which could be a sign of compromise.'
severity: Low
requiredDataConnectors:
  - connectorId: SecurityEvents
    dataTypes:
      - SecurityEvent
  - connectorId: WindowsSecurityEvents
    dataTypes:
      - SecurityEvent
  - connectorId: WindowsForwardedEvents
    dataTypes:
      - WindowsEvent
queryFrequency: 1d
queryPeriod: 1d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Persistence
  - PrivilegeEscalation
relevantTechniques:
  - T1098
  - T1078
query: |
  let WellKnownLocalSID = "S-1-5-32-5[0-9][0-9]$";
  let WellKnownGroupSID = "S-1-5-21-[0-9]*-[0-9]*-[0-9]*-5[0-9][0-9]$|S-1-5-21-[0-9]*-[0-9]*-[0-9]*-1102$|S-1-5-21-[0-9]*-[0-9]*-[0-9]*-1103$|S-1-5-21-[0-9]*-[0-9]*-[0-9]*-498$|S-1-5-21-[0-9]*-[0-9]*-[0-9]*-1000$";
  let AC_Add =
  (union isfuzzy=true
  (SecurityEvent
  // Event ID related to member addition.
  | where EventID in (4728, 4732,4756)
  | where TargetSid matches regex WellKnownLocalSID or TargetSid matches regex WellKnownGroupSID
  | parse EventData with * '"MemberName">' * '=' AccountAdded ",OU" *
  | where isnotempty(AccountAdded)
  | extend GroupAddedTo = TargetUserName, AddingAccount = Account
  | extend  AccountAdded_GroupAddedTo_AddingAccount = strcat(AccountAdded, "||", GroupAddedTo, "||", AddingAccount )
  | project AccountAdded_GroupAddedTo_AddingAccount, AccountAddedTime = TimeGenerated
  ),
  (WindowsEvent
  // Event ID related to member addition.
  | where EventID in (4728, 4732,4756)
  | extend TargetSid = tostring(EventData.TargetSid)
  | where TargetSid matches regex WellKnownLocalSID or TargetSid matches regex WellKnownGroupSID
  | parse EventData.MemberName with * '"MemberName">' * '=' AccountAdded ",OU" *
  | where isnotempty(AccountAdded)
  | extend TargetUserName = tostring(EventData.TargetUserName)
  | extend AddingAccount =  strcat(tostring(EventData.SubjectDomainName),"\\", tostring(EventData.SubjectUserName))
  | extend GroupAddedTo = TargetUserName
  | extend  AccountAdded_GroupAddedTo_AddingAccount = strcat(AccountAdded, "||", GroupAddedTo, "||", AddingAccount )
  | project AccountAdded_GroupAddedTo_AddingAccount, AccountAddedTime = TimeGenerated
  )
  );
  let AC_Remove =
  ( union isfuzzy=true
  (SecurityEvent
  // Event IDs related to member removal.
  | where EventID in (4729,4733,4757)
  | where TargetSid matches regex WellKnownLocalSID or TargetSid matches regex WellKnownGroupSID
  | parse EventData with * '"MemberName">' * '=' AccountRemoved ",OU" *
  | where isnotempty(AccountRemoved)
  | extend GroupRemovedFrom = TargetUserName, RemovingAccount = Account
  | extend AccountRemoved_GroupRemovedFrom_RemovingAccount = strcat(AccountRemoved, "||", GroupRemovedFrom, "||", RemovingAccount)
  | project AccountRemoved_GroupRemovedFrom_RemovingAccount, AccountRemovedTime = TimeGenerated, Computer, AccountRemoved = tolower(AccountRemoved),
  RemovingAccount, RemovingAccountLogonId = SubjectLogonId, GroupRemovedFrom = TargetUserName, TargetDomainName
  ),
  (WindowsEvent
  // Event IDs related to member removal.
  | where EventID in (4729,4733,4757)
  | extend TargetSid = tostring(EventData.TargetSid)
  | where TargetSid matches regex WellKnownLocalSID or TargetSid matches regex WellKnownGroupSID
  | parse EventData.MemberName with * '"MemberName">' * '=' AccountRemoved ",OU" *
  | where isnotempty(AccountRemoved)
  | extend TargetUserName = tostring(EventData.TargetUserName)
  | extend RemovingAccount =  strcat(tostring(EventData.SubjectDomainName),"\\", tostring(EventData.SubjectUserName))
  | extend GroupRemovedFrom = TargetUserName
  | extend AccountRemoved_GroupRemovedFrom_RemovingAccount = strcat(AccountRemoved, "||", GroupRemovedFrom, "||", RemovingAccount)
  | extend RemovedAccountLogonId= tostring(EventData.SubjectLogonId)
  | extend TargetDomainName = tostring(EventData.TargetDomainName)
  | project AccountRemoved_GroupRemovedFrom_RemovingAccount, AccountRemovedTime = TimeGenerated, Computer, AccountRemoved = tolower(AccountRemoved),
  RemovingAccount, RemovedAccountLogonId, GroupRemovedFrom = TargetUserName, TargetDomainName
  ));
  AC_Add
  | join kind = inner AC_Remove 
  on $left.AccountAdded_GroupAddedTo_AddingAccount == $right.AccountRemoved_GroupRemovedFrom_RemovingAccount
  | extend DurationinSecondAfter_Removed = datetime_diff ('second', AccountRemovedTime, AccountAddedTime)
  | where DurationinSecondAfter_Removed > 0
  | extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.'))
  | extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer)
  | extend RemovedAccountName = tostring(split(AccountRemoved, @"\")[1]), RemovedAccountNTDomain = tostring(split(AccountRemoved, @"\")[0])
  | extend RemovingAccountName = tostring(split(RemovingAccount, @"\")[1]), RemovingAccountNTDomain = tostring(split(RemovingAccount, @"\")[0])
  | project-away DomainIndex
entityMappings:
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: AccountRemoved
      - identifier: Name
        columnName: RemovedAccountName
      - identifier: NTDomain
        columnName: RemovedAccountNTDomain
  - entityType: Account
    fieldMappings:
      - identifier: FullName
        columnName: RemovingAccount
      - identifier: Name
        columnName: RemovingAccountName
      - identifier: NTDomain
        columnName: RemovingAccountNTDomain
  - entityType: Host
    fieldMappings:
      - identifier: FullName
        columnName: Computer
      - identifier: HostName
        columnName: HostName
      - identifier: NTDomain
        columnName: HostNameDomain
version: 1.1.5
kind: Scheduled
metadata:
    source:
        kind: Community
    author:
        name: Microsoft Security Research
    support:
        tier: Community
    categories:
        domains: [ "Security - Others", "Identity" ]

Stages and Predicates

Parameters

let WellKnownLocalSID = "S-1-5-32-5[0-9][0-9]$";

Let binding: `WellKnownGroupSID`

let WellKnownGroupSID = "S-1-5-21-[0-9]*-[0-9]*-[0-9]*-5[0-9][0-9]$|S-1-5-21-[0-9]*-[0-9]*-[0-9]*-1102$|S-1-5-21-[0-9]*-[0-9]*-[0-9]*-1103$|S-1-5-21-[0-9]*-[0-9]*-[0-9]*-498$|S-1-5-21-[0-9]*-[0-9]*-[0-9]*-1000$";

Let binding: `AC_Remove`

let AC_Remove = ( union isfuzzy=true
(SecurityEvent
| where EventID in (4729,4733,4757)
| where TargetSid matches regex WellKnownLocalSID or TargetSid matches regex WellKnownGroupSID
| parse EventData with * '"MemberName">' * '=' AccountRemoved ",OU" *
| where isnotempty(AccountRemoved)
| extend GroupRemovedFrom = TargetUserName, RemovingAccount = Account
| extend AccountRemoved_GroupRemovedFrom_RemovingAccount = strcat(AccountRemoved, "||", GroupRemovedFrom, "||", RemovingAccount)
| project AccountRemoved_GroupRemovedFrom_RemovingAccount, AccountRemovedTime = TimeGenerated, Computer, AccountRemoved = tolower(AccountRemoved),
RemovingAccount, RemovingAccountLogonId = SubjectLogonId, GroupRemovedFrom = TargetUserName, TargetDomainName
),
(WindowsEvent
| where EventID in (4729,4733,4757)
| extend TargetSid = tostring(EventData.TargetSid)
| where TargetSid matches regex WellKnownLocalSID or TargetSid matches regex WellKnownGroupSID
| parse EventData.MemberName with * '"MemberName">' * '=' AccountRemoved ",OU" *
| where isnotempty(AccountRemoved)
| extend TargetUserName = tostring(EventData.TargetUserName)
| extend RemovingAccount =  strcat(tostring(EventData.SubjectDomainName),"\\", tostring(EventData.SubjectUserName))
| extend GroupRemovedFrom = TargetUserName
| extend AccountRemoved_GroupRemovedFrom_RemovingAccount = strcat(AccountRemoved, "||", GroupRemovedFrom, "||", RemovingAccount)
| extend RemovedAccountLogonId= tostring(EventData.SubjectLogonId)
| extend TargetDomainName = tostring(EventData.TargetDomainName)
| project AccountRemoved_GroupRemovedFrom_RemovingAccount, AccountRemovedTime = TimeGenerated, Computer, AccountRemoved = tolower(AccountRemoved),
RemovingAccount, RemovedAccountLogonId, GroupRemovedFrom = TargetUserName, TargetDomainName
));

Derived from WellKnownLocalSID, WellKnownGroupSID.

union `isfuzzy=true` (2 sources)

Each leg below queries one source; the rule matches if any leg does. Sources: SecurityEvent, WindowsEvent

Leg 1: `SecurityEvent`

SecurityEvent
| where EventID in (4728, 4732,4756)
| where TargetSid matches regex WellKnownLocalSID or TargetSid matches regex WellKnownGroupSID
| parse EventData with * '"MemberName">' * '=' AccountAdded ",OU" *
| where isnotempty(AccountAdded)
| extend GroupAddedTo = TargetUserName, AddingAccount = Account
| extend  AccountAdded_GroupAddedTo_AddingAccount = strcat(AccountAdded, "||", GroupAddedTo, "||", AddingAccount )
| project AccountAdded_GroupAddedTo_AddingAccount, AccountAddedTime = TimeGenerated

Leg 2: `WindowsEvent`

WindowsEvent
| where EventID in (4728, 4732,4756)
| extend TargetSid = tostring(EventData.TargetSid)
| where TargetSid matches regex WellKnownLocalSID or TargetSid matches regex WellKnownGroupSID
| parse EventData.MemberName with * '"MemberName">' * '=' AccountAdded ",OU" *
| where isnotempty(AccountAdded)
| extend TargetUserName = tostring(EventData.TargetUserName)
| extend AddingAccount =  strcat(tostring(EventData.SubjectDomainName),"\\", tostring(EventData.SubjectUserName))
| extend GroupAddedTo = TargetUserName
| extend  AccountAdded_GroupAddedTo_AddingAccount = strcat(AccountAdded, "||", GroupAddedTo, "||", AddingAccount )
| project AccountAdded_GroupAddedTo_AddingAccount, AccountAddedTime = TimeGenerated

Applied to the combined result

| join kind = inner AC_Remove 
on $left.AccountAdded_GroupAddedTo_AddingAccount == $right.AccountRemoved_GroupRemovedFrom_RemovingAccount | extend DurationinSecondAfter_Removed = datetime_diff ('second', AccountRemovedTime, AccountAddedTime) | where DurationinSecondAfter_Removed > 0 | extend HostName = tostring(split(Computer, ".")[0]), DomainIndex = toint(indexof(Computer, '.')) | extend HostNameDomain = iff(DomainIndex != -1, substring(Computer, DomainIndex + 1), Computer) | extend RemovedAccountName = tostring(split(AccountRemoved, @"\")[1]), RemovedAccountNTDomain = tostring(split(AccountRemoved, @"\")[0]) | extend RemovingAccountName = tostring(split(RemovingAccount, @"\")[1]), RemovingAccountNTDomain = tostring(split(RemovingAccount, @"\")[0]) | project-away DomainIndex

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
`AccountAdded`	is_not_null	(no value, null check)
`AccountRemoved`	is_not_null	(no value, null check)
`DurationinSecondAfter_Removed`	gt	`0` transforms: `cased`
`EventID`	in	`4728` transforms: `cased` corpus 3 (splunk 3) `4729` transforms: `cased` `4732` transforms: `cased` corpus 4 (splunk 3, kusto 1) `4733` transforms: `cased` `4756` transforms: `cased` `4757` transforms: `cased`
`TargetSid`	regex_match	`S-1-5-21-[0-9]-[0-9]-[0-9]-5[0-9][0-9]$` `S-1-5-21-[0-9]-[0-9]-[0-9]-1102$` `S-1-5-21-[0-9]-[0-9]-[0-9]-1103$` `S-1-5-21-[0-9]-[0-9]-[0-9]-498$` `S-1-5-21-[0-9]-[0-9]-[0-9]*-1000$` corpus 3 (kusto 3) `S-1-5-32-5[0-9][0-9]$` corpus 3 (kusto 3)

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
`AccountAddedTime`	`project`
`AccountAdded_GroupAddedTo_AddingAccount`	`project`
`DurationinSecondAfter_Removed`	`extend`
`HostName`	`extend`
`HostNameDomain`	`extend`
`RemovedAccountNTDomain`	`extend`
`RemovedAccountName`	`extend`
`RemovingAccountNTDomain`	`extend`
`RemovingAccountName`	`extend`

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`f`	Follow link (`Shift` = new tab)
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`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)

Account added and removed from privileged groups

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: `WellKnownGroupSID`

Let binding: `AC_Remove`

union `isfuzzy=true` (2 sources)

Leg 1: `SecurityEvent`

Leg 2: `WindowsEvent`

Applied to the combined result

Indicators

Output fields

Keyboard shortcuts

Search operators

Account added and removed from privileged groups

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: WellKnownGroupSID

Let binding: AC_Remove

union isfuzzy=true (2 sources)

Leg 1: SecurityEvent

Leg 2: WindowsEvent

Applied to the combined result

Indicators

Output fields

Let binding: `WellKnownGroupSID`

Let binding: `AC_Remove`

union `isfuzzy=true` (2 sources)

Leg 1: `SecurityEvent`

Leg 2: `WindowsEvent`