Microsoft-Windows-Wmbclass-Opn

5 events across 1 channel

Event	Title	Channel	Sample
1	Sending command MessageType: MessageType, MessageLength: MessageLength, …	Operational	N
2	Receiving command done MessageType: MessageType, MessageLength: MessageLength, …	Operational	N
3	Receiving indication MessageType: MessageType, MessageLength: MessageLength, …	Operational	N
4	Receiving MessageType: MessageType, MessageLength: MessageLength, …	Operational	N
5	Receiving MessageType: MessageType, MessageLength: MessageLength, …	Operational	N

Event ID 1: Sending command MessageType: MessageType, MessageLength: MessageLength, MessageTransactionId: MessageTransactionId, TotalFragments: TotalFragments, CurrentFragment: CurrentFragment, ServiceId: Serv...

Provider: Microsoft-Windows-Wmbclass-Opn
Channel: Operational
Opcode: Info

Description

Sending command MessageType: , MessageLength: , MessageTransactionId: , TotalFragments: , CurrentFragment: , ServiceId: , CommandId: , CommandType: , InformationBufferLength: , InformationBuffer.

Message #

Sending command MessageType: %1, MessageLength: %2, MessageTransactionId: %3, TotalFragments: %4, CurrentFragment: %5, ServiceId: %6, CommandId: %7, CommandType: %8, InformationBufferLength: %9, InformationBuffer: %10

Fields #

Name	Description
`MessageType` UInt32
`MessageLength` UInt32
`MessageTransactionId` UInt32
`TotalFragments` UInt32
`CurrentFragment` UInt32
`ServiceId` GUID
`CommandId` UInt32
`CommandType` UInt32
`InformationBufferLength` UInt32
`InformationBuffer` Binary

Event ID 2: Receiving command done MessageType: MessageType, MessageLength: MessageLength, MessageTransactionId: MessageTransactionId, TotalFragments: TotalFragments, CurrentFragment: CurrentFragment, ServiceI...

Provider: Microsoft-Windows-Wmbclass-Opn
Channel: Operational
Opcode: Info

Description

Receiving command done MessageType: , MessageLength: , MessageTransactionId: , TotalFragments: , CurrentFragment: , ServiceId: , CommandId: , Status: , InformationBufferLength: , InformationBuffer.

Message #

Receiving command done MessageType: %1, MessageLength: %2, MessageTransactionId: %3, TotalFragments: %4, CurrentFragment: %5, ServiceId: %6, CommandId: %7, Status: %8, InformationBufferLength: %9, InformationBuffer: %10

Fields #

Name	Description
`MessageType` UInt32
`MessageLength` UInt32
`MessageTransactionId` UInt32
`TotalFragments` UInt32
`CurrentFragment` UInt32
`ServiceId` GUID
`CommandId` UInt32
`Status` UInt32	NTSTATUS reference
`InformationBufferLength` UInt32
`InformationBuffer` Binary

Event ID 3: Receiving indication MessageType: MessageType, MessageLength: MessageLength, MessageTransactionId: MessageTransactionId, TotalFragments: TotalFragments, CurrentFragment: CurrentFragment, ServiceId:...

Provider: Microsoft-Windows-Wmbclass-Opn
Channel: Operational
Opcode: Info

Description

Receiving indication MessageType: , MessageLength: , MessageTransactionId: , TotalFragments: , CurrentFragment: , ServiceId: , CommandId: , InformationBufferLength: , InformationBuffer.

Message #

Receiving indication MessageType: %1, MessageLength: %2, MessageTransactionId: %3, TotalFragments: %4, CurrentFragment: %5, ServiceId: %6, CommandId: %7, InformationBufferLength: %8, InformationBuffer: %9

Fields #

Name	Description
`MessageType` UInt32
`MessageLength` UInt32
`MessageTransactionId` UInt32
`TotalFragments` UInt32
`CurrentFragment` UInt32
`ServiceId` GUID
`CommandId` UInt32
`InformationBufferLength` UInt32
`InformationBuffer` Binary

Event ID 4: Receiving MessageType: MessageType, MessageLength: MessageLength, MessageTransactionId: MessageTransactionId, Uint32 payload: Status.

Provider: Microsoft-Windows-Wmbclass-Opn
Channel: Operational
Opcode: Info

Description

Receiving MessageType: MessageType, MessageLength: MessageLength, MessageTransactionId: MessageTransactionId, Uint32 payload: Status.

Message #

Receiving MessageType: %1, MessageLength: %2, MessageTransactionId: %3, Uint32 payload: %4

Fields #

Name	Description
`MessageType` UInt32
`MessageLength` UInt32
`MessageTransactionId` UInt32
`Status` UInt32	NTSTATUS reference

Event ID 5: Receiving MessageType: MessageType, MessageLength: MessageLength, MessageTransactionId: MessageTransactionId.

Provider: Microsoft-Windows-Wmbclass-Opn
Channel: Operational
Opcode: Info

Description

Receiving MessageType: MessageType, MessageLength: MessageLength, MessageTransactionId: MessageTransactionId.

Message #

Receiving MessageType: %1, MessageLength: %2, MessageTransactionId: %3

Fields #

Name	Description
`MessageType` UInt32
`MessageLength` UInt32
`MessageTransactionId` UInt32

Provenance

Where this provider's schema came from, and which Windows build it was observed on. Windows can change a provider's event schema between builds, so use this to judge whether it matches the build you collect from.

ETW provider GUID a42fe227-a7bf-4483-a502-6bcda428cd96

Defined in mbbcx.sys, the binary that emits these events.

Observed on:

Win11-26200.6584, schema read from the registered manifest, binary version 10.0.26100.6584, captured 2026-06-02

Downloads

Microsoft-Windows-Wmbclass-Opn registered manifest XML (in the Win11-26200.6584 manifest pack, 2.0 MB) manifest-xml

`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)

Microsoft-Windows-Wmbclass-Opn

Event ID 1: Sending command MessageType: MessageType, MessageLength: MessageLength, MessageTransactionId: MessageTransactionId, TotalFragments: TotalFragments, CurrentFragment: CurrentFragment, ServiceId: Serv...

Description

Message #

Fields #

Event ID 2: Receiving command done MessageType: MessageType, MessageLength: MessageLength, MessageTransactionId: MessageTransactionId, TotalFragments: TotalFragments, CurrentFragment: CurrentFragment, ServiceI...

Description

Message #

Fields #

Event ID 3: Receiving indication MessageType: MessageType, MessageLength: MessageLength, MessageTransactionId: MessageTransactionId, TotalFragments: TotalFragments, CurrentFragment: CurrentFragment, ServiceId:...

Description

Message #

Fields #

Event ID 4: Receiving MessageType: MessageType, MessageLength: MessageLength, MessageTransactionId: MessageTransactionId, Uint32 payload: Status.

Description

Message #

Fields #

Event ID 5: Receiving MessageType: MessageType, MessageLength: MessageLength, MessageTransactionId: MessageTransactionId.

Description

Message #

Fields #

Provenance

Downloads

Keyboard shortcuts

Search operators