Detect credential add to Connect Sync Application

Author: Robbe Van den Daele
Source: github.com/HybridBrothers/Hunting-Queries-Detection-Rules

This detection specifically flags credentials being added to the Connect Sync Application in Entra ID, a technique known to have persistance from On-premise AD DS to Entra ID. It tries to look at both certificate, client secret, and federated credentials being added, and tries to remove legitimate renewal processes. Since the legitimate renewal process first adds a new certificate only te remove the old one short after, we by default allow for a maximum of 1 minute between the certificate create and delete events.

MITRE ATT&CK coverage

Tactic	Techniques
Initial Access	`T1078.004` Valid Accounts: Cloud Accounts
Persistence	`T1078.004` Valid Accounts: Cloud Accounts, `T1098.001` Account Manipulation: Additional Cloud Credentials, `T1556.007` Modify Authentication Process: Hybrid Identity
Privilege Escalation	`T1078.004` Valid Accounts: Cloud Accounts, `T1098.001` Account Manipulation: Additional Cloud Credentials
Stealth	`T1078.004` Valid Accounts: Cloud Accounts
Defense Impairment	`T1556.007` Modify Authentication Process: Hybrid Identity
Credential Access	`T1556.007` Modify Authentication Process: Hybrid Identity

References

https://specterops.io/blog/2025/06/09/update-dumping-entra-connect-sync-credentials/

Event coverage

Provider	Event	Title
Entra-AuditLogs	_catch_all	Entra ID audit event (any operation)

Rule body yaml

// Flag adding credential that does not look like a renewal
let base = materialize (
    AuditLogs
    // Search events happening on the Sync Account
    | extend AppName = tostring(TargetResources[0].displayName)
    | where AppName startswith "ConnectSyncProvisioning_"
    // Only get cretificate or secret changes
    | where OperationName has_any ("Add service principal", "Certificates and secrets management", "Update application")
    // Expand the target resources and modified properties, and only use events ralted to KeyDescription
    | mv-expand TargetResources
    | extend ModifiedProperties = TargetResources.modifiedProperties
    | mv-expand ModifiedProperties
    | where ModifiedProperties.displayName == "KeyDescription"
    // Save the old and new values of the secrets on the application
    | extend OldValue = tostring(ModifiedProperties.oldValue), 
        NewValue = tostring(ModifiedProperties.newValue)
    // Save the old and new credential names in an array
    | extend OldCredentialNames = extract_all(@"DisplayName=([^\]]+)", dynamic([1]), OldValue),
        NewCredentialNames = extract_all(@"DisplayName=([^\]]+)", dynamic([1]), NewValue)
);
let newCredsAdd = (
    base
    // Flag when there are more new credentials than old ones
    | where array_length(OldCredentialNames) < array_length(NewCredentialNames)
    | project-rename NewCredAddTimeGenerated = TimeGenerated
);
let credRemove = (
    base
    // Get events where credentials are being removed
    | where array_length(OldCredentialNames) > array_length(NewCredentialNames)
    | project-rename CredRemoveTimeGenerated = TimeGenerated
);
// Only flag when credentials are added without another being removed for the same application within a small time window
// This excludes a normal renewal process
newCredsAdd
| join kind=leftouter credRemove on AppName
| where CredRemoveTimeGenerated - NewCredAddTimeGenerated > 1m
| project NewCredAddTimeGenerated, CredRemoveTimeGenerated, OperationName, AdditionalDetails, InitiatedBy, AppName, ModifiedProperties, OldCredentialNames, NewCredentialNames

Stages and Predicates

Let binding: `credRemove`

let credRemove = (
    base
    | where array_length(OldCredentialNames) > array_length(NewCredentialNames)
    | project-rename CredRemoveTimeGenerated = TimeGenerated
);

Derived from base.

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

Stage 1: `source`

AuditLogs

Stage 2: `extend`

| extend AppName = tostring(TargetResources[0].displayName)

Stage 3: `where`

| where AppName startswith "ConnectSyncProvisioning_"

Stage 4: `where`

| where OperationName has_any ("Add service principal", "Certificates and secrets management", "Update application")

Stage 5: `mv-expand`

| mv-expand TargetResources

Stage 6: `extend`

| extend ModifiedProperties = TargetResources.modifiedProperties

Stage 7: `mv-expand`

| mv-expand ModifiedProperties

Stage 8: `where`

| where ModifiedProperties.displayName == "KeyDescription"

Stage 9: `extend`

| extend OldValue = tostring(ModifiedProperties.oldValue), 
        NewValue = tostring(ModifiedProperties.newValue)

Stage 10: `extend`

| extend OldCredentialNames = extract_all(@"DisplayName=([^\]]+)", dynamic([1]), OldValue),
        NewCredentialNames = extract_all(@"DisplayName=([^\]]+)", dynamic([1]), NewValue)

Stage 11: `where`

| where array_length(OldCredentialNames) < array_length(NewCredentialNames)

Stage 12: `project-rename`

| project-rename NewCredAddTimeGenerated = TimeGenerated

The stages below run on newCredsAdd (the outer pipeline).

Stage 13: `join`

newCredsAdd
| join kind=leftouter credRemove on AppName

Stage 14: `where` where CredRemoveTimeGenerated - NewCredAddTimeGenerated > 1m

| where CredRemoveTimeGenerated - NewCredAddTimeGenerated > 1m

Stage 15: `project`

| project NewCredAddTimeGenerated, CredRemoveTimeGenerated, OperationName, AdditionalDetails, InitiatedBy, AppName, ModifiedProperties, OldCredentialNames, NewCredentialNames

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
`AppName`	starts_with	`ConnectSyncProvisioning_`
`OldCredentialNames`	cross_field_compare	`NewCredentialNames` transforms: `op:lt`, `lhs:array_length`, `rhs:array_length`
`OperationName`	match	`Add service principal` `Certificates and secrets management` `Update application`
`displayName`	eq	`KeyDescription` 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
`AdditionalDetails`	`project`
`AppName`	`project`
`CredRemoveTimeGenerated`	`project`
`InitiatedBy`	`project`
`ModifiedProperties`	`project`
`NewCredAddTimeGenerated`	`project`
`NewCredentialNames`	`project`
`OldCredentialNames`	`project`
`OperationName`	`project`

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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)

Detect credential add to Connect Sync Application

MITRE ATT&CK coverage

References

Event coverage

Rule body yaml

Stages and Predicates

Let binding: `credRemove`

Stage 1: `source`

Stage 2: `extend`

Stage 3: `where`

Stage 4: `where`

Stage 5: `mv-expand`

Stage 6: `extend`

Stage 7: `mv-expand`

Stage 8: `where`

Stage 9: `extend`

Stage 10: `extend`

Stage 11: `where`

Stage 12: `project-rename`

Stage 13: `join`

Stage 14: `where` where CredRemoveTimeGenerated - NewCredAddTimeGenerated > 1m

Stage 15: `project`

Indicators

Output fields

Keyboard shortcuts

Search operators

Detect credential add to Connect Sync Application

MITRE ATT&CK coverage

References

Event coverage

Rule body yaml

Stages and Predicates

Let binding: credRemove

Stage 1: source

Stage 2: extend

Stage 3: where

Stage 4: where

Stage 5: mv-expand

Stage 6: extend

Stage 7: mv-expand

Stage 8: where

Stage 9: extend

Stage 10: extend

Stage 11: where

Stage 12: project-rename

Stage 13: join

Stage 14: where where CredRemoveTimeGenerated - NewCredAddTimeGenerated > 1m

Stage 15: project

Indicators

Output fields

Let binding: `credRemove`

Stage 1: `source`

Stage 2: `extend`

Stage 3: `where`

Stage 4: `where`

Stage 5: `mv-expand`

Stage 6: `extend`

Stage 7: `mv-expand`

Stage 8: `where`

Stage 9: `extend`

Stage 10: `extend`

Stage 11: `where`

Stage 12: `project-rename`

Stage 13: `join`

Stage 14: `where` where CredRemoveTimeGenerated - NewCredAddTimeGenerated > 1m

Stage 15: `project`