MpSigStub.exe
Summary
Microsoft Protection Signature Stub - temporary process used during Windows Defender signature (definition) updates.
MpSigStub.exe is the 322nd most commonly executed Windows program in EchoTrail's dataset, observed 28,452 times across enterprise environments. It typically runs from C:\Windows\System32 and it is most often launched by AM_Delta.exe.
Behavior
Top Paths
- C:\Windows\System3292.99%
- C:\Windows\Temp\...4.2%
- C:\Windows\SoftwareDistribution\Download\Install1.31%
- C:\Windows\SERVIC~1\NETWOR~1\AppData\Local\Temp\...0.96%
- C:\Windows\SERVIC~2\NETWOR~1\AppData\Local\Temp\...0.13%
- C:\Windows\SERVIC~3\NETWOR~1\AppData\Local\Temp\...0.05%
- C:\Windows\SystemTemp\1D37F759-DEF1-44D2-9C8A-79EEFC14BA8B0.01%
- C:\Users\...<0.01%
- C:\Windows\SystemTemp\0193E21E-75F2-4731-8810-8FC9A088E09B<0.01%
- C:\Windows\SystemTemp\0485A7D1-B22B-4841-BB7E-4095EBB74A40<0.01%
Top Hashes (SHA256)
- fa42b9b84754e2e8368e8929fa045be86dbd72678176ee75814d2a16d23e5c2623.06%
- d0772bfb0687e068d4d21749c90dbac7fb7f71f74f3a8caf6d69cac483a1c17f12.49%
- 0bc408c801441239f72d7df3dd6edbcdfb5313d6ae5a04c0a13e8c2dfc39f6d810.45%
- 489663a32ce72a60fb45d6f88a391ef17eb1aa97554a3fd7867c8f6decb35bc79.87%
- f3bf989add4b18e246cdab149df46b71c8fe5315875ffc988b7289be737d4ec09.82%
- 0bb339c22fb53e6bc8f8475590d8549f5432f45cf61337db15d0d2ff552324bb8.29%
- a20a90f00b76ff248107fc105705cfe0545530ba0cfaa25f3eb7afab769af04c8.06%
- e0355c48c099a023bcebf2d477e476e9d57657025f5a0658a2bd00e75d89f95f4.42%
- 896f1793ca8bda909a71217f41a93af5a06354c1ea9ea81c975d429224b28e192.95%
- 071b0d3a08503a8b88aeeda1d20f371a563377028f6e252dc66cce60ab8f823e2.29%
Process Ancestry
Top Grandparents
- MpCmdRun.exe100%
Top Parents
- AM_Delta.exe21.2%
- wuauclt.exe5.75%
- updateplatform.exe3.34%
- AM_Base_Patch1.exe1.76%
- AM_Engine.exe0.83%
- AM_Base.exe0.2%
- wuaucltcore.exe0.1%
Top Children
- MpRecovery.exe100%
Rare or environment-specific process names are omitted from ancestry tables. Percentages are of all observed relationships.
Security Analysis
What does MpSigStub.exe normally do?
Runs briefly during Defender definition updates to extract and apply new signature files.
When is MpSigStub.exe suspicious?
Persistent execution (should be brief). Running from non-standard paths.
False positive notes
Brief execution during Defender updates is normal.
Related Processes
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Data from EchoTrail's dataset of ~346M Windows process executions. Last extracted 2026-08-04.