Rare Process as a Service

Status: available
Severity: medium
Time window: 14d
Group by: DeviceName, ServiceProcess, ServiceProcessCmdline, ServiceProcessCreationTime, ServiceProcessID, ServiceProcessSHA1, ServiceProcessUser
Source: github.com/Azure/Azure-Sentinel

This query is looking for rarely seen processes which are launched as a service. Whiltelisted process list need to be updated based on the environment. Author: Jouni Mikkola More info: https://threathunt.blog/rare-process-launch-as-a-service/

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1543.003` Create or Modify System Process: Windows Service

Event coverage

Provider	Event/ActionType	Title
Sysmon	Event ID 1	Process creation
Security-Auditing	Event ID 4688	A new process has been created.
Defender-DeviceProcessEvents	any	Process activity (any)

Rule body kusto

id: 91a451e3-178f-41b2-9e5d-da97d75b9971
name: Rare Process as a Service
description: |
  This query is looking for rarely seen processes which are launched as a service. Whiltelisted process list need to be updated based on the environment.
  Author: Jouni Mikkola
  More info: https://threathunt.blog/rare-process-launch-as-a-service/
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: MicrosoftThreatProtection
    dataTypes:
      - DeviceProcessEvents
      - DeviceNetworkEvents
      - DeviceFileEvents
      - DeviceImageLoadEvents
queryFrequency: 1d
queryPeriod: 14d
triggerOperator: gt
triggerThreshold: 0
tactics:
  - Persistence
relevantTechniques:
  - T1543
  - T1543.003
query: |
  let LookupTime = 14d;
  let WhiteList = pack_array(
  "svchost.exe",
  "mssense.exe",
  "msmpeng.exe",
  "searchindexer.exe",
  "microsoftedgeupdate.exe"
  );
  let GetServices = materialize (
  DeviceProcessEvents
  | where TimeGenerated > ago(LookupTime)
  | where InitiatingProcessParentFileName contains "services.exe"
  | where InitiatingProcessFileName !in~(WhiteList)
  | project TimeGenerated, DeviceName, StartedChildProcess = FileName, StartedChildProcessSHA1 = SHA1, StartedChildProcessCmdline = ProcessCommandLine, ServiceProcessSHA1 = InitiatingProcessSHA1, ServiceProcess = InitiatingProcessFileName, ServiceProcessCmdline = InitiatingProcessCommandLine, ServiceProcessID = InitiatingProcessId, ServiceProcessCreationTime = InitiatingProcessCreationTime, ServiceProcessUser = InitiatingProcessAccountName
  );
  GetServices
  | summarize count() by ServiceProcess, DeviceName
  | where count_ < 6 
  | join kind = inner GetServices on ServiceProcess, DeviceName 
  | join kind = leftouter ( 
  DeviceNetworkEvents 
  | where TimeGenerated > ago(LookupTime)
  | where InitiatingProcessParentFileName contains "services.exe"
  | where InitiatingProcessFileName !in~(WhiteList)
  | project TimeGenerated, DeviceName, ServiceProcessSHA1 = InitiatingProcessSHA1, ServiceProcess = InitiatingProcessFileName, ServiceProcessCmdline = InitiatingProcessCommandLine, ServiceProcessID = InitiatingProcessId, ServiceProcessCreationTime = InitiatingProcessCreationTime, ServiceProcessUser = InitiatingProcessAccountName, NetworkAction = ActionType, RemoteIP, RemoteUrl
  ) on DeviceName, ServiceProcess, ServiceProcessCmdline, ServiceProcessCreationTime, ServiceProcessID, ServiceProcessUser, ServiceProcessSHA1
  | join kind = leftouter (
  DeviceFileEvents
  | where TimeGenerated > ago(LookupTime)
  | where InitiatingProcessParentFileName contains "services.exe"
  | where InitiatingProcessFileName !in~(WhiteList)
  | project TimeGenerated, DeviceName, ServiceProcessSHA1 = InitiatingProcessSHA1, ServiceProcess = InitiatingProcessFileName, ServiceProcessCmdline = InitiatingProcessCommandLine, ServiceProcessID = InitiatingProcessId, ServiceProcessCreationTime = InitiatingProcessCreationTime, ServiceProcessUser = InitiatingProcessAccountName, FileAction = ActionType, ModifiedFile = FileName, ModifiedFileSHA1 = SHA1, ModifiedFilePath = FolderPath
  ) on DeviceName, ServiceProcess, ServiceProcessCmdline, ServiceProcessCreationTime, ServiceProcessID, ServiceProcessUser, ServiceProcessSHA1
  | join kind = leftouter (
  DeviceImageLoadEvents
  | where TimeGenerated > ago(LookupTime)
  | where InitiatingProcessParentFileName contains "services.exe"
  | where InitiatingProcessFileName !in~(WhiteList)
  | project TimeGenerated, DeviceName, ServiceProcessSHA1 = InitiatingProcessSHA1, ServiceProcess = InitiatingProcessFileName, ServiceProcessCmdline = InitiatingProcessCommandLine, ServiceProcessID = InitiatingProcessId, ServiceProcessCreationTime = InitiatingProcessCreationTime, ServiceProcessUser = InitiatingProcessAccountName, LoadedDLL = FileName, LoadedDLLSHA1 = SHA1, LoadedDLLPath = FolderPath
  ) on DeviceName, ServiceProcess, ServiceProcessCmdline, ServiceProcessCreationTime, ServiceProcessID, ServiceProcessUser, ServiceProcessSHA1
  | summarize ConnectedAddresses = make_set(RemoteIP, 100000), ConnectedUrls = make_set(RemoteUrl, 100000), FilesModified = make_set(ModifiedFile, 100000),FileModFolderPath = make_set(ModifiedFilePath, 100000),FileModHA1s = make_set(ModifiedFileSHA1, 100000), ChildProcesses = make_set(StartedChildProcess, 100000), ChildCommandlines = make_set(StartedChildProcessCmdline, 100000), DLLsLoaded = make_set(LoadedDLL, 100000), DLLSHA1 = make_set(LoadedDLLSHA1, 100000) by DeviceName, ServiceProcess, ServiceProcessCmdline, ServiceProcessCreationTime, ServiceProcessID, ServiceProcessUser, ServiceProcessSHA1
  | extend HostName = iff(DeviceName has '.', substring(DeviceName, 0, indexof(DeviceName, '.')), DeviceName)
  | extend DnsDomain = iff(DeviceName has '.', substring(DeviceName, indexof(DeviceName, '.') + 1), "")
entityMappings:
  - entityType: Host
    fieldMappings:
      - identifier: FullName
        columnName: DeviceName
      - identifier: HostName
        columnName: HostName
      - identifier: DnsDomain
        columnName: DnsDomain
  - entityType: Process
    fieldMappings:
      - identifier: ProcessId
        columnName: ServiceProcessID
      - identifier: CommandLine
        columnName: ServiceProcessCmdline
version: 1.0.0
kind: Scheduled

Stages and Predicates

Parameters

let LookupTime = 14d;

Let binding: `WhiteList`

let WhiteList = pack_array(
"svchost.exe",
"mssense.exe",
"msmpeng.exe",
"searchindexer.exe",
"microsoftedgeupdate.exe"
);

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

Stage 1: `source`

DeviceProcessEvents

Stage 2: `where`

| where TimeGenerated > ago(LookupTime)

Stage 3: `where`

| where InitiatingProcessParentFileName contains "services.exe"

Stage 4: `where`

| where InitiatingProcessFileName !in~(WhiteList)

References WhiteList (defined above).

Stage 5: `project`

| project TimeGenerated, DeviceName, StartedChildProcess = FileName, StartedChildProcessSHA1 = SHA1, StartedChildProcessCmdline = ProcessCommandLine, ServiceProcessSHA1 = InitiatingProcessSHA1, ServiceProcess = InitiatingProcessFileName, ServiceProcessCmdline = InitiatingProcessCommandLine, ServiceProcessID = InitiatingProcessId, ServiceProcessCreationTime = InitiatingProcessCreationTime, ServiceProcessUser = InitiatingProcessAccountName

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

Stage 6: `summarize`

GetServices
| summarize count() by ServiceProcess, DeviceName

Stage 7: `where`

| where count_ < 6

Stage 8: `join`

| join kind = inner GetServices on ServiceProcess, DeviceName

Stage 9: `join`

| join kind = leftouter ( 
DeviceNetworkEvents 
| where TimeGenerated > ago(LookupTime)
| where InitiatingProcessParentFileName contains "services.exe"
| where InitiatingProcessFileName !in~(WhiteList)
| project TimeGenerated, DeviceName, ServiceProcessSHA1 = InitiatingProcessSHA1, ServiceProcess = InitiatingProcessFileName, ServiceProcessCmdline = InitiatingProcessCommandLine, ServiceProcessID = InitiatingProcessId, ServiceProcessCreationTime = InitiatingProcessCreationTime, ServiceProcessUser = InitiatingProcessAccountName, NetworkAction = ActionType, RemoteIP, RemoteUrl
) on DeviceName, ServiceProcess, ServiceProcessCmdline, ServiceProcessCreationTime, ServiceProcessID, ServiceProcessUser, ServiceProcessSHA1

Stage 10: `join`

| join kind = leftouter (
DeviceFileEvents
| where TimeGenerated > ago(LookupTime)
| where InitiatingProcessParentFileName contains "services.exe"
| where InitiatingProcessFileName !in~(WhiteList)
| project TimeGenerated, DeviceName, ServiceProcessSHA1 = InitiatingProcessSHA1, ServiceProcess = InitiatingProcessFileName, ServiceProcessCmdline = InitiatingProcessCommandLine, ServiceProcessID = InitiatingProcessId, ServiceProcessCreationTime = InitiatingProcessCreationTime, ServiceProcessUser = InitiatingProcessAccountName, FileAction = ActionType, ModifiedFile = FileName, ModifiedFileSHA1 = SHA1, ModifiedFilePath = FolderPath
) on DeviceName, ServiceProcess, ServiceProcessCmdline, ServiceProcessCreationTime, ServiceProcessID, ServiceProcessUser, ServiceProcessSHA1

Stage 11: `join`

| join kind = leftouter (
DeviceImageLoadEvents
| where TimeGenerated > ago(LookupTime)
| where InitiatingProcessParentFileName contains "services.exe"
| where InitiatingProcessFileName !in~(WhiteList)
| project TimeGenerated, DeviceName, ServiceProcessSHA1 = InitiatingProcessSHA1, ServiceProcess = InitiatingProcessFileName, ServiceProcessCmdline = InitiatingProcessCommandLine, ServiceProcessID = InitiatingProcessId, ServiceProcessCreationTime = InitiatingProcessCreationTime, ServiceProcessUser = InitiatingProcessAccountName, LoadedDLL = FileName, LoadedDLLSHA1 = SHA1, LoadedDLLPath = FolderPath
) on DeviceName, ServiceProcess, ServiceProcessCmdline, ServiceProcessCreationTime, ServiceProcessID, ServiceProcessUser, ServiceProcessSHA1

Stage 12: `summarize`

| summarize ConnectedAddresses = make_set(RemoteIP, 100000), ConnectedUrls = make_set(RemoteUrl, 100000), FilesModified = make_set(ModifiedFile, 100000),FileModFolderPath = make_set(ModifiedFilePath, 100000),FileModHA1s = make_set(ModifiedFileSHA1, 100000), ChildProcesses = make_set(StartedChildProcess, 100000), ChildCommandlines = make_set(StartedChildProcessCmdline, 100000), DLLsLoaded = make_set(LoadedDLL, 100000), DLLSHA1 = make_set(LoadedDLLSHA1, 100000) by DeviceName, ServiceProcess, ServiceProcessCmdline, ServiceProcessCreationTime, ServiceProcessID, ServiceProcessUser, ServiceProcessSHA1

Stage 13: `extend`

| extend HostName = iff(DeviceName has '.', substring(DeviceName, 0, indexof(DeviceName, '.')), DeviceName)

HostName =

ifDeviceName has "."substring(DeviceName, 0, indexof(DeviceName, '.'))

elseDeviceName

Stage 14: `extend`

| extend DnsDomain = iff(DeviceName has '.', substring(DeviceName, indexof(DeviceName, '.') + 1), "")

DnsDomain =

ifDeviceName has "."substring(DeviceName, (indexof(DeviceName, '.') + 1))

else""

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

Field	Kind	Excluded values
`InitiatingProcessFileName`	eq	`WhiteList`
`InitiatingProcessFileName`	eq	`WhiteList`
`InitiatingProcessFileName`	eq	`WhiteList`
`InitiatingProcessFileName`	eq	`WhiteList`
`InitiatingProcessFileName`	eq	`WhiteList`

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
`InitiatingProcessParentFileName`	contains	`services.exe`
`count_`	lt	`6` 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
`ChildCommandlines`	`summarize`
`ChildProcesses`	`summarize`
`ConnectedAddresses`	`summarize`
`ConnectedUrls`	`summarize`
`DLLSHA1`	`summarize`
`DLLsLoaded`	`summarize`
`DeviceName`	`summarize`
`FileModFolderPath`	`summarize`
`FileModHA1s`	`summarize`
`FilesModified`	`summarize`
`ServiceProcess`	`summarize`
`ServiceProcessCmdline`	`summarize`
`ServiceProcessCreationTime`	`summarize`
`ServiceProcessID`	`summarize`
`ServiceProcessSHA1`	`summarize`
`ServiceProcessUser`	`summarize`
`HostName`	`extend`
`DnsDomain`	`extend`

`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)

Rare Process as a Service

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: `WhiteList`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `project`

Stage 6: `summarize`

Stage 7: `where`

Stage 8: `join`

Stage 9: `join`

Stage 10: `join`

Stage 11: `join`

Stage 12: `summarize`

Stage 13: `extend`

Stage 14: `extend`

Exclusions

Indicators

Output fields

Keyboard shortcuts

Search operators

Rare Process as a Service

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Parameters

Let binding: WhiteList

Stage 1: source

Stage 2: where

Stage 3: where

Stage 4: where

Stage 5: project

Stage 6: summarize

Stage 7: where

Stage 8: join

Stage 9: join

Stage 10: join

Stage 11: join

Stage 12: summarize

Stage 13: extend

Stage 14: extend

Exclusions

Indicators

Output fields

Let binding: `WhiteList`

Stage 1: `source`

Stage 2: `where`

Stage 3: `where`

Stage 4: `where`

Stage 5: `project`

Stage 6: `summarize`

Stage 7: `where`

Stage 8: `join`

Stage 9: `join`

Stage 10: `join`

Stage 11: `join`

Stage 12: `summarize`

Stage 13: `extend`

Stage 14: `extend`