DCOM Lateral Movement

Status: available
Severity: medium
Time window: 1h
Group by: DCOMCmdLine, DCOMHostPID, DCOMPID, DeviceId, DeviceName, InitiatingProcessId, InitiatingProcessParentId, LastBootTime, LocalIP, RemoteIP, TimestampNetwEventExact, TimestampProcEventExact
Source: github.com/Azure/Azure-Sentinel

This detection looks for cases of close-time proximity between incoming network traffic on RPC/TCP, followed by the creation of a DCOM object, followed by the creation of a child process of the DCOM object. The query first identifies incoming network traffic over RPC/TCP, followed by the creation of a DCOM object (process) within 2 seconds, followed by the creation of a child process of this DCOM object.

MITRE ATT&CK coverage

Tactic	Techniques
Lateral Movement	`T1021.003` Remote Services: Distributed Component Object Model

Event coverage

Provider	Event/ActionType	Title
Sysmon	Event ID 3	Network connection
Security-Auditing	Event ID 5156	The Windows Filtering Platform has permitted a connection.
Defender-DeviceNetworkEvents	any	Network activity (any)

Rule body kusto

id: d58035ff-0bac-4c61-a7f4-f58939ff9764
name: DCOM Lateral Movement
description: |
  This detection looks for cases of close-time proximity between incoming network traffic on RPC/TCP, followed by the creation of a DCOM object, followed by the creation of a child process of the DCOM object. 
  The query first identifies incoming network traffic over RPC/TCP, followed by the creation of a DCOM object (process) within 2 seconds, followed by the creation of a child process of this DCOM object. 
severity: Medium
status: Available
requiredDataConnectors:
  - connectorId: MicrosoftThreatProtection
    dataTypes:
      - DeviceProcessEvents
      - DeviceNetworkEvents
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
  - LateralMovement
relevantTechniques:
  - T1021.003
query: |
  let allowListedExecs = dynamic(["TiWorker.exe", "dllhost.exe", "backgroundTaskHost.exe", "mobsync.exe", "WmiPrvSE.exe", "RuntimeBroker.exe", "smartscreen.exe", "SppExtComObj.Exe", "usocoreworker.exe", "browser_broker.exe", "ssoncom.exe"]);
  let rpcNetwEvents = materialize(DeviceNetworkEvents
  | where InitiatingProcessFileName =~ "svchost.exe" and InitiatingProcessCommandLine has "rpcss" and LocalPort == 135
  | where LocalIP !~ RemoteIP and ActionType != "ListeningConnectionCreated"
  | project TimestampNetwEvent=bin(Timestamp, 5s),TimestampNetwEventExact=Timestamp, DeviceId, DeviceName, RPCHostID=InitiatingProcessId, RPCHostFileName=InitiatingProcessFileName, LocalIP, RemoteIP);
  let dcomProcEvents = materialize (DeviceProcessEvents
  | where InitiatingProcessFileName =~ "svchost.exe" and InitiatingProcessCommandLine has "dcomlaunch"
  | project TimestampProcEvent=bin(Timestamp, 5s),TimestampProcEventExact=Timestamp, DeviceId, DeviceName, DCOMHostPID=InitiatingProcessId, DCOMHostFileName=InitiatingProcessFileName, DCOMPID=ProcessId, DCOMFileName=FileName, DCOMCmdLine=ProcessCommandLine);
  let lastBootTime = materialize(DeviceProcessEvents
  | where FileName =~ "services.exe"
  | summarize LastBootTime=max(Timestamp) by DeviceId);
  let RemoteDcomProcs = materialize(rpcNetwEvents
  | join kind=inner dcomProcEvents on DeviceId 
  | join kind=leftouter lastBootTime on DeviceId
  | where TimestampProcEvent > LastBootTime+5m // Ignore first 5 min after boot.
  // Avoiding < 2 since if the time between netw and proc creation is negative, they can't be related. Network event must come first. 
  | where datetime_diff("second", TimestampProcEventExact, TimestampNetwEventExact) between (0 .. 2) 
  // Allow-listing some usual suspects which create lot of noise. This is dangerous though...huge gap for bypass. 
  | where DCOMFileName  !in~ (allowListedExecs));
  RemoteDcomProcs
  | join kind=inner hint.strategy=broadcast (
      DeviceProcessEvents 
      | where InitiatingProcessParentFileName =~ "svchost.exe" and InitiatingProcessFileName in ((RemoteDcomProcs | project DCOMFileName))) 
  on $left.DCOMHostPID == $right.InitiatingProcessParentId, DeviceId, $left.DCOMPID == $right.InitiatingProcessId
  | where InitiatingProcessParentFileName =~ "svchost.exe" and InitiatingProcessFileName =~ DCOMFileName 
  // Allow-listing the magic of Defender.
  | where FileName !in~ ("csc.exe") 
  | summarize make_set(ProcessCommandLine) by TimestampNetwEventExact, TimestampProcEventExact, DeviceId, DeviceName, InitiatingProcessId, LocalIP, RemoteIP, LastBootTime, DCOMCmdLine
entityMappings:
  - entityType: Host
    fieldMappings:
      - identifier: FullName
        columnName: DeviceName
  - entityType: IP
    fieldMappings:
      - identifier: Address
        columnName: RemoteIP 
  - entityType: Process
    fieldMappings:
      - identifier: CommandLine
        columnName: DCOMCmdLine
version: 1.0.0
kind: Scheduled

Stages and Predicates

Let binding: `allowListedExecs`

let allowListedExecs = dynamic(["TiWorker.exe", "dllhost.exe", "backgroundTaskHost.exe", "mobsync.exe", "WmiPrvSE.exe", "RuntimeBroker.exe", "smartscreen.exe", "SppExtComObj.Exe", "usocoreworker.exe", "browser_broker.exe", "ssoncom.exe"]);

Let binding: `dcomProcEvents`

let dcomProcEvents = materialize (DeviceProcessEvents
| where InitiatingProcessFileName =~ "svchost.exe" and InitiatingProcessCommandLine has "dcomlaunch"
| project TimestampProcEvent=bin(Timestamp, 5s),TimestampProcEventExact=Timestamp, DeviceId, DeviceName, DCOMHostPID=InitiatingProcessId, DCOMHostFileName=InitiatingProcessFileName, DCOMPID=ProcessId, DCOMFileName=FileName, DCOMCmdLine=ProcessCommandLine);

Let binding: `lastBootTime`

let lastBootTime = materialize(DeviceProcessEvents
| where FileName =~ "services.exe"
| summarize LastBootTime=max(Timestamp) by DeviceId);

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

Stage 1: `source`

rpcNetwEvents

Stage 2: `join`

join kind=inner (...)

Stage 3: `join`

join kind=leftouter (...)

Stage 4: `where` where TimestampProcEvent - LastBootTime > 5m

where ...

Stage 5: `where` where TimestampProcEventExact - TimestampNetwEventExact >= 0s AND TimestampProcEventExact - TimestampNetwEventExact <= 2s

where ...

Stage 6: `where`

where not (DCOMFileName in~ ("RuntimeBroker.exe", "SppExtComObj.Exe", "TiWorker.exe", "WmiPrvSE.exe", "backgroundTaskHost.exe", "browser_broker.exe", "dllhost.exe", "mobsync.exe", "smartscreen.exe", "ssoncom.exe", "usocoreworker.exe"))

References allowListedExecs (defined above).

Stage 7: `join`

join kind=inner (...)

Stage 8: `where`

where InitiatingProcessFileName =~ "DCOMFileName" and InitiatingProcessParentFileName =~ "svchost.exe"

Stage 9: `where`

where not (FileName =~ "csc.exe")

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

Stage 10: `summarize`

summarize by TimestampNetwEventExact, TimestampProcEventExact, DeviceId, DeviceName, InitiatingProcessId, LocalIP, RemoteIP, LastBootTime, DCOMCmdLine

Exclusions

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

Field	Kind	Excluded values
`DCOMFileName`	in	`RuntimeBroker.exe`, `SppExtComObj.Exe`, `TiWorker.exe`, `WmiPrvSE.exe`, `backgroundTaskHost.exe`, `browser_broker.exe`, `dllhost.exe`, `mobsync.exe`, `smartscreen.exe`, `ssoncom.exe`, `usocoreworker.exe`
`FileName`	eq	`csc.exe`

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
`FileName`	eq	`services.exe`
`InitiatingProcessCommandLine`	match	`dcomlaunch` transforms: `term`
`InitiatingProcessFileName`	eq	`DCOMFileName` `svchost.exe` corpus 13 (elastic 6, splunk 5, kusto 2)
`InitiatingProcessParentFileName`	eq	`svchost.exe`

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
`DCOMCmdLine`	`summarize`
`DeviceId`	`summarize`
`DeviceName`	`summarize`
`InitiatingProcessId`	`summarize`
`LastBootTime`	`summarize`
`LocalIP`	`summarize`
`RemoteIP`	`summarize`
`TimestampNetwEventExact`	`summarize`
`TimestampProcEventExact`	`summarize`

`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)

DCOM Lateral Movement

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Let binding: `allowListedExecs`

Let binding: `dcomProcEvents`

Let binding: `lastBootTime`

Stage 1: `source`

Stage 2: `join`

Stage 3: `join`

Stage 4: `where` where TimestampProcEvent - LastBootTime > 5m

Stage 5: `where` where TimestampProcEventExact - TimestampNetwEventExact >= 0s AND TimestampProcEventExact - TimestampNetwEventExact <= 2s

Stage 6: `where`

Stage 7: `join`

Stage 8: `where`

Stage 9: `where`

Stage 10: `summarize`

Exclusions

Indicators

Output fields

Keyboard shortcuts

Search operators

DCOM Lateral Movement

MITRE ATT&CK coverage

Event coverage

Rule body kusto

Stages and Predicates

Let binding: allowListedExecs

Let binding: dcomProcEvents

Let binding: lastBootTime

Stage 1: source

Stage 2: join

Stage 3: join

Stage 4: where where TimestampProcEvent - LastBootTime > 5m

Stage 5: where where TimestampProcEventExact - TimestampNetwEventExact >= 0s AND TimestampProcEventExact - TimestampNetwEventExact <= 2s

Stage 6: where

Stage 7: join

Stage 8: where

Stage 9: where

Stage 10: summarize

Exclusions

Indicators

Output fields

Let binding: `allowListedExecs`

Let binding: `dcomProcEvents`

Let binding: `lastBootTime`

Stage 1: `source`

Stage 2: `join`

Stage 3: `join`

Stage 4: `where` where TimestampProcEvent - LastBootTime > 5m

Stage 5: `where` where TimestampProcEventExact - TimestampNetwEventExact >= 0s AND TimestampProcEventExact - TimestampNetwEventExact <= 2s

Stage 6: `where`

Stage 7: `join`

Stage 8: `where`

Stage 9: `where`

Stage 10: `summarize`