Detect Multiple Hello for Business PRT tokens being used simultaneously for one device.

Group by: CurrentSessionID, DeviceID
Author: Robbe Van den Daele
Source: github.com/HybridBrothers/Hunting-Queries-Detection-Rules

This detection rule tries to find multiple PRT tokens being used simultaneously for one device. This might indicate that an attacker was able to request a new PRT on a second device using exxported Windows Hello for Business keys. More information about the attack scenario can be found in the references.

MITRE ATT&CK coverage

Tactic	Techniques
Credential Access	`T1606` Forge Web Credentials

References

https://hybridbrothers.com/detecting-non-privileged-windows-hello-abuse/

Rule body yaml

// Get the Sign-in logs we want to query
let base = materialize(
    SigninLogs
    | where Timestamp > ago(1d)
);
// Get all the WHfB signins by looking at the authentication method and incomming token
let whfb = (
    base
    // Get WHfB signins
    | mv-expand todynamic(AuthenticationDetails)
    | where AuthenticationDetails.authenticationMethod == "Windows Hello for Business"
    | where IncomingTokenType == "primaryRefreshToken"
    | extend DeviceID = tostring(DeviceDetail.deviceId), AuthenticationDateTime = todatetime(AuthenticationDetails.authenticationStepDateTime)
    // Remove empty Session and Device IDs
    | where SessionId != "" and DeviceID != ""
);
// Save the time frame for each WHfB PRT token
// We use the SessionID to identify a specific PRT token since the SessionID changes when a new refresh token is being used
let prt_timeframes = (
    whfb
    // Summarize the first and last PRT usage per device, by using the Session ID
    | summarize TimeMin = arg_min(AuthenticationDateTime,*), TimeMax=arg_max(AuthenticationDateTime,*) by DeviceID, SessionId
    | project DeviceID, SessionId, TimeMin, TimeMax
);
// Save all the Session IDs for the logins that came from a WHfB authentication method
let whfb_sessions = toscalar(
    whfb
    | summarize make_set(SessionId)
);
base
| mv-expand todynamic(AuthenticationDetails)
| extend DeviceID = tostring(DeviceDetail.deviceId), AuthenticationDateTime = todatetime(AuthenticationDetails.authenticationStepDateTime)
// Get all signins related to a WHfB Session
| where SessionId in (whfb_sessions)
// Join the access token requests comming from a WHfB session with all the PRT tokens used in the past for each device
| join kind=inner prt_timeframes on DeviceID
| extend CurrentSessionID = SessionId, OtherSessionID = SessionId1, OtherSessionTimeMin = TimeMin, OtherSessionTimeMax = TimeMax, DeviceName = tostring(DeviceDetail.displayName)
// Get logins where the current SessionID is not the same as another one
| where CurrentSessionID != OtherSessionID
// Check if the new Session ID is seen while other Session IDs are still active (only check first login of the current Session ID)
| summarize arg_min(AuthenticationDateTime, *) by DeviceID, CurrentSessionID
| where AuthenticationDateTime between (OtherSessionTimeMin .. OtherSessionTimeMax)
// Exclude Windows Sign In as application login since attackers will use the PRT to request access tokens for other applications (they do not need to signin into Windows anymore)
| where AppDisplayName != "Windows Sign In"
| project AuthenticationDateTime, UserPrincipalName, DeviceID, DeviceName, CurrentSessionID, OtherSessionID, OtherSessionTimeMin, OtherSessionTimeMax, AppDisplayName, ResourceDisplayName

// Get the Sign-in logs we want to query
let base = materialize(
    SigninLogs
    | where TimeGenerated > ago(1d)
);
// Get all the WHfB signins by looking at the authentication method and incomming token
let whfb = (
    base
    // Get WHfB signins
    | mv-expand todynamic(AuthenticationDetails)
    | where AuthenticationDetails.authenticationMethod == "Windows Hello for Business"
    | where IncomingTokenType == "primaryRefreshToken"
    | extend DeviceID = tostring(DeviceDetail.deviceId), AuthenticationDateTime = todatetime(AuthenticationDetails.authenticationStepDateTime)
    // Remove empty Session and Device IDs
    | where SessionId != "" and DeviceID != ""
);
// Save the time frame for each WHfB PRT token
// We use the SessionID to identify a specific PRT token since the SessionID changes when a new refresh token is being used
let prt_timeframes = (
    whfb
    // Summarize the first and last PRT usage per device, by using the Session ID
    | summarize TimeMin = arg_min(AuthenticationDateTime,*), TimeMax=arg_max(AuthenticationDateTime,*) by DeviceID, SessionId
    | project DeviceID, SessionId, TimeMin, TimeMax
);
// Save all the Session IDs for the logins that came from a WHfB authentication method
let whfb_sessions = toscalar(
    whfb
    | summarize make_set(SessionId)
);
base
| mv-expand todynamic(AuthenticationDetails)
| extend DeviceID = tostring(DeviceDetail.deviceId), AuthenticationDateTime = todatetime(AuthenticationDetails.authenticationStepDateTime)
// Get all signins related to a WHfB Session
| where SessionId in (whfb_sessions)
// Join the access token requests comming from a WHfB session with all the PRT tokens used in the past for each device
| join kind=inner prt_timeframes on DeviceID
| extend CurrentSessionID = SessionId, OtherSessionID = SessionId1, OtherSessionTimeMin = TimeMin, OtherSessionTimeMax = TimeMax, DeviceName = tostring(DeviceDetail.displayName)
// Get logins where the current SessionID is not the same as another one
| where CurrentSessionID != OtherSessionID
// Check if the new Session ID is seen while other Session IDs are still active (only check first login of the current Session ID)
| summarize arg_min(AuthenticationDateTime, *) by DeviceID, CurrentSessionID
| where AuthenticationDateTime between (OtherSessionTimeMin .. OtherSessionTimeMax)
// Exclude Windows Sign In as application login since attackers will use the PRT to request access tokens for other applications (they do not need to signin into Windows anymore)
| where AppDisplayName != "Windows Sign In"
| project AuthenticationDateTime, UserPrincipalName, DeviceID, DeviceName, CurrentSessionID, OtherSessionID, OtherSessionTimeMin, OtherSessionTimeMax, AppDisplayName, ResourceDisplayName

Stages and Predicates

Let binding: `whfb`

let whfb = (
    base
    | mv-expand todynamic(AuthenticationDetails)
    | where AuthenticationDetails.authenticationMethod == "Windows Hello for Business"
    | where IncomingTokenType == "primaryRefreshToken"
    | extend DeviceID = tostring(DeviceDetail.deviceId), AuthenticationDateTime = todatetime(AuthenticationDetails.authenticationStepDateTime)
    | where SessionId != "" and DeviceID != ""
);

Derived from base.

Let binding: `prt_timeframes`

let prt_timeframes = (
    whfb
    | summarize TimeMin = arg_min(AuthenticationDateTime,*), TimeMax=arg_max(AuthenticationDateTime,*) by DeviceID, SessionId
    | project DeviceID, SessionId, TimeMin, TimeMax
);

Derived from whfb.

Let binding: `whfb_sessions`

let whfb_sessions = toscalar(
    whfb
    | summarize make_set(SessionId)
);

Derived from whfb.

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

Stage 1: `source`

SigninLogs

Stage 2: `where`

| where Timestamp > ago(1d)

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

Stage 3: `mv-expand`

base
| mv-expand todynamic(AuthenticationDetails)

Stage 4: `extend`

| extend DeviceID = tostring(DeviceDetail.deviceId), AuthenticationDateTime = todatetime(AuthenticationDetails.authenticationStepDateTime)

Stage 5: `where`

| where SessionId in (whfb_sessions)

References whfb_sessions (defined above).

Stage 6: `join`

| join kind=inner prt_timeframes on DeviceID

Stage 7: `extend`

| extend CurrentSessionID = SessionId, OtherSessionID = SessionId1, OtherSessionTimeMin = TimeMin, OtherSessionTimeMax = TimeMax, DeviceName = tostring(DeviceDetail.displayName)

Stage 8: `where`

| where CurrentSessionID != OtherSessionID

Stage 9: `summarize`

| summarize arg_min(AuthenticationDateTime, *) by DeviceID, CurrentSessionID

Stage 10: `where`

| where AuthenticationDateTime between (OtherSessionTimeMin .. OtherSessionTimeMax)

Stage 11: `where`

| where AppDisplayName != "Windows Sign In"

Stage 12: `project`

| project AuthenticationDateTime, UserPrincipalName, DeviceID, DeviceName, CurrentSessionID, OtherSessionID, OtherSessionTimeMin, OtherSessionTimeMax, AppDisplayName, ResourceDisplayName

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
`AppDisplayName`	ne	`Windows Sign In` transforms: `cased`
`AuthenticationDateTime`	ge	`OtherSessionTimeMin`
`AuthenticationDateTime`	le	`OtherSessionTimeMax`
`CurrentSessionID`	ne	`OtherSessionID` transforms: `cased`
`IncomingTokenType`	eq	`primaryRefreshToken` transforms: `cased`
`SessionId`	in	`whfb_sessions` transforms: `cased`
`authenticationMethod`	eq	`Windows Hello for Business` 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
`AppDisplayName`	`project`
`AuthenticationDateTime`	`project`
`CurrentSessionID`	`project`
`DeviceID`	`project`
`DeviceName`	`project`
`OtherSessionID`	`project`
`OtherSessionTimeMax`	`project`
`OtherSessionTimeMin`	`project`
`ResourceDisplayName`	`project`
`UserPrincipalName`	`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)

Detect Multiple Hello for Business PRT tokens being used simultaneously for one device.

MITRE ATT&CK coverage

References

Rule body yaml

Stages and Predicates

Let binding: `whfb`

Let binding: `prt_timeframes`

Let binding: `whfb_sessions`

Stage 1: `source`

Stage 2: `where`

Stage 3: `mv-expand`

Stage 4: `extend`

Stage 5: `where`

Stage 6: `join`

Stage 7: `extend`

Stage 8: `where`

Stage 9: `summarize`

Stage 10: `where`

Stage 11: `where`

Stage 12: `project`

Indicators

Output fields

Keyboard shortcuts

Search operators

Detect Multiple Hello for Business PRT tokens being used simultaneously for one device.

MITRE ATT&CK coverage

References

Rule body yaml

Stages and Predicates

Let binding: whfb

Let binding: prt_timeframes

Let binding: whfb_sessions

Stage 1: source

Stage 2: where

Stage 3: mv-expand

Stage 4: extend

Stage 5: where

Stage 6: join

Stage 7: extend

Stage 8: where

Stage 9: summarize

Stage 10: where

Stage 11: where

Stage 12: project

Indicators

Output fields

Let binding: `whfb`

Let binding: `prt_timeframes`

Let binding: `whfb_sessions`

Stage 1: `source`

Stage 2: `where`

Stage 3: `mv-expand`

Stage 4: `extend`

Stage 5: `where`

Stage 6: `join`

Stage 7: `extend`

Stage 8: `where`

Stage 9: `summarize`

Stage 10: `where`

Stage 11: `where`

Stage 12: `project`