Microsoft-Windows-Serial-ClassExtension-V2

32 events across 2 channels

Event	Title	Channel	Sample
1	SerCx2 loaded (ControlDeviceName).	Analytic	N
2	SerCx2 failed to load (Status).	System	N
3	SerCx2 unloading.	Analytic	N
4	Starting rundown.	Analytic	N
5	Device rundown (Device).	Analytic	N
6	Rundown complete.	Analytic	N
7	Device created (Device).	Analytic	N
8	Device destroyed (Device).	Analytic	N
9	TransmitSM (TransferSmContext) Event: Event.	Analytic	N
10	TransmitSM (TransferSmContext) Transition: FromState[Event] -> ToState.	Analytic	N
11	Invalid Transition TransmitSM (TransferSmContext) Transition: FromState[Event] …	Analytic	N
12	ReceiveSM (TransferSmContext) Event: Event.	Analytic	N
13	ReceiveSM (TransferSmContext) Transition: FromState[Event] -> ToState.	Analytic	N
14	Invalid Transition ReceiveSM (TransferSmContext) Transition: FromState[Event] -> …	Analytic	N
15	Processing IOCTL.	Analytic	N
16	Completed IOCTL with Status.	Analytic	N
17	Transmit I/O request for Length bytes started.	Analytic	N
18	Transmit I/O request completed (Status).	Analytic	N
19	Transmit I/O chunk of Length bytes using TransferModeEvent.	Analytic	N
20	Receive I/O request for Length bytes started.	Analytic	N
21	Receive I/O request completed (Status).	Analytic	N
22	Receive I/O chunk of Length bytes using TransferModeEvent.	Analytic	N
23	Saved BytesSaved bytes before exiting D0.	Analytic	N
24	Transitioning to system power state TargetState.	Analytic	N
25	Transitioning to device power state TargetState.	Analytic	N
26	System power state transition TargetState complete (Status).	Analytic	N
27	Device power state transition TargetState complete (Status).	Analytic	N
28	Event Event.	Analytic	N
29	TransmitSM (TransferSmContext) Event: Event.	Analytic	N
30	TransmitSM (TransferSmContext) Transition: FromState[Event] -> ToState.	Analytic	N
31	ReceiveSM (TransferSmContext) Event: Event.	Analytic	N
32	ReceiveSM (TransferSmContext) Transition: FromState[Event] -> ToState.	Analytic	N

Event ID 1: SerCx2 loaded (ControlDeviceName).

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Opcode: Info

Description

SerCx2 loaded (ControlDeviceName).

Message #

SerCx2 loaded (%1).

Fields #

Name	Description
`ControlDeviceName` UnicodeString

Event ID 2: SerCx2 failed to load (Status).

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: System
Opcode: Info

Description

SerCx2 failed to load (Status).

Message #

SerCx2 failed to load (%2).

Fields #

Name	Description
`ControlDeviceName` UnicodeString
`Status` HexInt32	NTSTATUS reference

Event ID 3: SerCx2 unloading.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Opcode: Info

Description

SerCx2 unloading.

Message #

SerCx2 unloading.

Event ID 4: Starting rundown.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: Rundownevents.
Opcode: Start

Description

Starting rundown.

Message #

Starting rundown.

Event ID 5: Device rundown (Device).

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: Rundownevents.

Description

Device rundown (Device).

Message #

Device rundown (%1).

Fields #

Name	Description
`Device` Pointer
`TransmitTransferSmContext` Pointer
`ReceiveTransferSmContext` Pointer
`DeviceInstanceId` UnicodeString

Event ID 6: Rundown complete.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: Rundownevents.
Opcode: Stop

Description

Rundown complete.

Message #

Rundown complete.

Event ID 7: Device created (Device).

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Opcode: Info

Description

Device created (Device).

Message #

Device created (%1).

Fields #

Name	Description
`Device` Pointer
`TransmitTransferSmContext` Pointer
`ReceiveTransferSmContext` Pointer
`DeviceInstanceId` UnicodeString

Event ID 8: Device destroyed (Device).

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Opcode: Info

Description

Device destroyed (Device).

Message #

Device destroyed (%1).

Fields #

Name	Description
`Device` Pointer

Event ID 9: TransmitSM (TransferSmContext) Event: Event.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: I/OStateMachineoperation.

Description

TransmitSM (TransferSmContext) Event: Event.

Message #

TransmitSM (%1) Event: %2

Fields #

Name	Description
`TransferSmContext` Pointer
`Event` HexInt32

Event ID 10: TransmitSM (TransferSmContext) Transition: FromState[Event] -> ToState.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: I/OStateMachineoperation.

Description

TransmitSM (TransferSmContext) Transition: FromState[Event] -> ToState.

Message #

TransmitSM (%1) Transition: %2[%3] -> %4

Fields #

Name	Description
`TransferSmContext` Pointer
`FromState` HexInt32
`Event` HexInt32
`ToState` HexInt32

Event ID 11: Invalid Transition TransmitSM (TransferSmContext) Transition: FromState[Event] -> ToState.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.

Description

Invalid Transition TransmitSM (TransferSmContext) Transition: FromState[Event] -> ToState.

Message #

Invalid Transition TransmitSM (%1) Transition: %2[%3] -> %4

Fields #

Name	Description
`TransferSmContext` Pointer
`FromState` HexInt32
`Event` HexInt32
`ToState` HexInt32

Event ID 12: ReceiveSM (TransferSmContext) Event: Event.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: I/OStateMachineoperation.

Description

ReceiveSM (TransferSmContext) Event: Event.

Message #

ReceiveSM (%1) Event: %2

Fields #

Name	Description
`TransferSmContext` Pointer
`Event` HexInt32

Event ID 13: ReceiveSM (TransferSmContext) Transition: FromState[Event] -> ToState.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: I/OStateMachineoperation.

Description

ReceiveSM (TransferSmContext) Transition: FromState[Event] -> ToState.

Message #

ReceiveSM (%1) Transition: %2[%3] -> %4

Fields #

Name	Description
`TransferSmContext` Pointer
`FromState` HexInt32
`Event` HexInt32
`ToState` HexInt32

Event ID 14: Invalid Transition ReceiveSM (TransferSmContext) Transition: FromState[Event] -> ToState.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.

Description

Invalid Transition ReceiveSM (TransferSmContext) Transition: FromState[Event] -> ToState.

Message #

Invalid Transition ReceiveSM (%1) Transition: %2[%3] -> %4

Fields #

Name	Description
`TransferSmContext` Pointer
`FromState` HexInt32
`Event` HexInt32
`ToState` HexInt32

Event ID 15: Processing IOCTL.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: IOCTLrequest.
Opcode: Start

Description

Processing IOCTL.

Message #

Processing %2.

Fields #

Name	Description
`Device` Pointer
`IOCTL` HexInt32
`IOCTLInputBufferLength` HexInt32
`IOCTLInputBuffer` Binary

Event ID 16: Completed IOCTL with Status.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: IOCTLrequest.
Opcode: Stop

Description

Completed IOCTL with Status.

Message #

Completed %2 with %3.

Fields #

Name	Description
`Device` Pointer
`IOCTL` HexInt32
`Status` HexInt32	NTSTATUS reference
`IOCTLOutputBufferLength` HexInt32
`IOCTLOutputBuffer` Binary

Event ID 17: Transmit I/O request for Length bytes started.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: Start

Description

Transmit I/O request for Length bytes started.

Message #

Transmit I/O request for %2 bytes started.

Fields #

Name	Description
`Device` Pointer
`Length` UInt64

Event ID 18: Transmit I/O request completed (Status).

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: Stop

Description

Transmit I/O request completed (Status).

Message #

Transmit I/O request completed (%2).

Fields #

Name	Description
`Device` Pointer
`Status` HexInt32	NTSTATUS reference
`Information` UInt64

Event ID 19: Transmit I/O chunk of Length bytes using TransferModeEvent.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: I/Opayloadoperation.

Description

Transmit I/O chunk of Length bytes using TransferModeEvent.

Message #

Transmit I/O chunk of %3 bytes using %4.

Fields #

Name	Description
`Device` Pointer
`Offset` UInt64
`Length` UInt32
`TransferModeEvent` HexInt32
`Payload` Binary

Event ID 20: Receive I/O request for Length bytes started.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: Start

Description

Receive I/O request for Length bytes started.

Message #

Receive I/O request for %2 bytes started.

Fields #

Name	Description
`Device` Pointer
`Length` UInt64

Event ID 21: Receive I/O request completed (Status).

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: Stop

Description

Receive I/O request completed (Status).

Message #

Receive I/O request completed (%2).

Fields #

Name	Description
`Device` Pointer
`Status` HexInt32	NTSTATUS reference
`Information` UInt64

Event ID 22: Receive I/O chunk of Length bytes using TransferModeEvent.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: I/Opayloadoperation.

Description

Receive I/O chunk of Length bytes using TransferModeEvent.

Message #

Receive I/O chunk of %3 bytes using %4.

Fields #

Name	Description
`Device` Pointer
`Offset` UInt64
`Length` UInt32
`TransferModeEvent` HexInt32
`Payload` Binary

Event ID 23: Saved BytesSaved bytes before exiting D0.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.

Description

Saved BytesSaved bytes before exiting D0. Total TotalBytes bytes.

Message #

Saved %2 bytes before exiting D0. Total %3 bytes.

Fields #

Name	Description
`Device` Pointer
`BytesSaved` UInt32
`TotalBytes` UInt32

Event ID 24: Transitioning to system power state TargetState.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: Powerstatetransitions.
Opcode: Start

Description

Transitioning to system power state TargetState.

Message #

Transitioning to system power state %2.

Fields #

Name	Description
`Device` Pointer
`TargetState` HexInt32

Event ID 25: Transitioning to device power state TargetState.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: Powerstatetransitions.
Opcode: Start

Description

Transitioning to device power state TargetState.

Message #

Transitioning to device power state %2.

Fields #

Name	Description
`Device` Pointer
`TargetState` HexInt32

Event ID 26: System power state transition TargetState complete (Status).

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: Powerstatetransitions.
Opcode: Stop

Description

System power state transition TargetState complete (Status).

Message #

System power state transition %2 complete (%3).

Fields #

Name	Description
`Device` Pointer
`TargetState` HexInt32
`Status` HexInt32	NTSTATUS reference

Event ID 27: Device power state transition TargetState complete (Status).

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: Powerstatetransitions.
Opcode: Stop

Description

Device power state transition TargetState complete (Status).

Message #

Device power state transition %2 complete (%3).

Fields #

Name	Description
`Device` Pointer
`TargetState` HexInt32
`Status` HexInt32	NTSTATUS reference

Event ID 28: Event Event.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.

Description

Event Event.

Message #

Event %2.

Fields #

Name	Description
`Device` Pointer
`Event` HexInt32

Event ID 29: TransmitSM (TransferSmContext) Event: Event.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: I/OStateMachineoperation.

Description

TransmitSM (TransferSmContext) Event: Event.

Message #

TransmitSM (%1) Event: %2

Fields #

Name	Description
`TransferSmContext` Pointer
`Event` HexInt32

Event ID 30: TransmitSM (TransferSmContext) Transition: FromState[Event] -> ToState.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: I/OStateMachineoperation.

Description

TransmitSM (TransferSmContext) Transition: FromState[Event] -> ToState.

Message #

TransmitSM (%1) Transition: %2[%3] -> %4

Fields #

Name	Description
`TransferSmContext` Pointer
`FromState` HexInt32
`Event` HexInt32
`ToState` HexInt32

Event ID 31: ReceiveSM (TransferSmContext) Event: Event.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: I/OStateMachineoperation.

Description

ReceiveSM (TransferSmContext) Event: Event.

Message #

ReceiveSM (%1) Event: %2

Fields #

Name	Description
`TransferSmContext` Pointer
`Event` HexInt32

Event ID 32: ReceiveSM (TransferSmContext) Transition: FromState[Event] -> ToState.

Provider: Microsoft-Windows-Serial-ClassExtension-V2
Channel: Analytic
Task: I/Orequest.
Opcode: I/OStateMachineoperation.

Description

ReceiveSM (TransferSmContext) Transition: FromState[Event] -> ToState.

Message #

ReceiveSM (%1) Transition: %2[%3] -> %4

Fields #

Name	Description
`TransferSmContext` Pointer
`FromState` HexInt32
`Event` HexInt32
`ToState` HexInt32

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 eee173ef-7ed2-45de-9877-01c70a852fbd

Defined in SerCx2.sys, the binary that emits these events.

Observed on:

WS2022-20348.4893, schema read from the registered manifest, binary version 10.0.20348.1, captured 2026-06-02
Win11-26200.6584, schema read from the registered manifest, binary version 10.0.26100.1150, captured 2026-06-02

`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)