Microsoft Security Essentials content scan callback to the service.

Below is a stack when a MSE file system filter(WdFilter.sys) called a service(MsMpEng.exe) to perform file content scan on file open.


00 nt!KiSwapContext

01 nt!KiSwapThread
02 nt!KiCommitThreadWait
03 nt!KeWaitForMultipleObjects
04 nt!FsRtlCancellableWaitForMultipleObjects
05 FLTMGR!FltSendMessage
06 WdFilter!MpScanFile
07 WdFilter!MpAmPostCreate
08 WdFilter!MpPostCreate
09 FLTMGR!FltpPerformPostCallbacks
0a FLTMGR!FltpPassThroughCompletionWorker
0b FLTMGR!FltpLegacyProcessingAfterPreCallbacksCompleted
0c FLTMGR!FltpCreate
16 nt!IopParseDevice
17 nt!ObpLookupObjectName
18 nt!ObOpenObjectByNameEx
19 nt!IopCreateFile
1a nt!NtCreateFile
1b nt!KiSystemServiceCopyEnd
1c ntdll!NtCreateFile

In response the service sent an IOCTL to the filter to create a section( i.e. a mapped file) for data scan

0b mup!MupStateMachine
0c mup!MupFsControl
0d FLTMGR!FltpLegacyProcessingAfterPreCallbacksCompleted
0e FLTMGR!FltPerformSynchronousIo
0f FLTMGR!IssueControlOperation
10 FLTMGR!FltFsControlFile
11 FLTMGR!FltpSetPurgeFailureMode
12 FLTMGR!FltCreateSectionForDataScan
13 WdFilter!MpCreateSection
14 WdFilter!MpMessage
15 FLTMGR!FltpFilterMessage
16 FLTMGR!FltpMsgDispatch
17 FLTMGR!FltpDispatch
21 nt!IopSynchronousServiceTail
22 nt!IopXxxControlFile
23 nt!NtDeviceIoControlFile
24 nt!KiSystemServiceCopyEnd
25 ntdll!NtDeviceIoControlFile