Is winmm.dll safe?
Only Cynet flagged this unsigned DLL among 75 engines, while tier-1 scanners, sandbox results, child inspection, and researcher intelligence provided no malware corroboration.
Only 1 of 75 engines flagged the DLL, and that result came from a low-trust detector without a named family. Seventeen tier-1 engines found nothing, while one sandbox recorded no malware-exclusive techniques or malicious verdict; however, the file is unsigned and child-file conclusions remain incomplete.
c2b1436e008af56001…8f54747267edf5Recommended next actions
Before using
Use it only as part of software obtained from the developer's official site or another source you independently trust.
If you already used it
Keep normal device protection enabled and stop if the file behaves unexpectedly.
Intelligence
The saved assessment, checked against the scan evidence and recorded coverage.
The reasoning behind this verdict
This section explains the evidence supporting the verdict and keeps conflicting or missing signals visible.
Only 1 of 75 engines flagged the DLL, and that result came from a low-trust detector without a named family. Seventeen tier-1 engines found nothing, while one sandbox recorded no malware-exclusive techniques or malicious verdict; however, the file is unsigned and child-file conclusions remain incomplete.
Cynet alone flagged the sample among 75 engines, and its generic score is unsupported by any tier-1 detector. One completed sandbox produced no malicious verdict and no malware-exclusive offensive techniques, although it recorded environment-awareness and other common activity. None of eight inspected children was identified as malicious, but all eight lack conclusive individual verdicts. Static analysis found no likely packing or high-entropy code, and three external intelligence checks supplied no corroborating hit. The DLL is unsigned, and no complete contacted-host reputation result exists, so those areas do not provide additional assurance.
What We Detected
Cynet was the only engine to flag the file out of 75, using a generic malicious score rather than a named malware family. No tier-1 engine detected it, including Avast, BitDefender, ESET, Fortinet, Kaspersky, and others represented in the results.
Threat Behavior
One sandbox run recorded 11 ambient techniques but no malware-exclusive offensive techniques and no malicious sandbox verdict. The environment-awareness indicators T1497 and T1497.001 deserve context, but they are insufficient without stronger behavior or detection corroboration. Eight written child hashes were inspected without a malicious result, though their individual verdicts remain unknown. The sample made no observed network contacts during that run; contacted-host reputation was not checked or saved.
What To Do Now
Keep endpoint protection enabled and obtain the DLL from its official software source when possible. If its origin is uncertain or it appeared unexpectedly in a system directory, verify the parent application and quarantine it pending publisher confirmation.
Where this verdict could be wrong4 caveats
- signing.applicable=true and signing.signed=false — the DLL has no verified publisher identity.
- The sample carries the file tag detect-debug-environment and includes T1497/T1497.001, which can indicate environment awareness but is not malware-exclusive here.
- droppedChildren.rollup.unknown=8, so the absence of a known malicious child is not equivalent to eight confirmed-benign children.
- contactedHosts=null, so no complete host-reputation cross-check is available.
These are the assessment's weak points. If you believe one applies to your file, report the verdict and we'll re-review it.
- Only 1/75 engines detected the sample, and the sole detection came from Cynet at low-trust tier.
- All 17 tier-1 engines reported clean.
- One sandbox produced no malicious verdict and no offensive techniques.
- No inspected child was identified as malicious.
- No packing, high-entropy code, YARAify rule, CIRCL hit, or MalwareBazaar hit was found.
- The Win32 DLL is unsigned despite code signing being applicable.
- T1497 and T1497.001 indicate environment-awareness behavior in the sandbox.
- All eight inspected child hashes have unknown individual verdicts.
- No complete contacted-host reputation cross-check is available.
Keep security protection enabled and use the DLL only if its origin and associated application are trusted. Recheck or quarantine it if it appeared unexpectedly or cannot be matched to an official installation.
Coverage & freshness
Complete means the check returned a usable result. It does not mean the file is safe.
Antivirus
Complete1 of 75 engines flagged the file.
Sandbox
Complete1 isolated runtime environment contributed observations.
Network
Not runNo contacted-host reputation check is recorded.
No timestamp recordedYARA
CompleteRule evaluation completed with no recorded matches.
External intel
Complete3 of 3 independent reference sources completed.
Behavior
Plain-English impact first, then the observed runtime evidence.
Runtime flight recorder
Capture complete- 1isolated sandbox run
- 11MITRE ATT&CK techniques
- 12spawned processes
- 0network contacts
- 40filesystem & mutex artifacts
What this file did when executed
This file was detonated in 1 sandbox and its runtime behaviour was observed.
Adversary techniques mapped to the MITRE ATT&CK framework.
- \REGISTRY\A\{d8911f9c-0114-70f5-5325-78bb8343ca60}\Root\InventoryApplicationFile\PermissionsCheckTestKey
- \REGISTRY\A\{802940a7-6266-6fd4-65df-2fb442907154}\Root\InventoryApplicationFile\PermissionsCheckTestKey
- C:\ProgramData\Microsoft\Windows\WER\ReportArchive\597fea61-0f2f-4f35-be93-bda8c9b3cd7a
- C:\ProgramData\Microsoft\Windows\WER\ReportArchive\8115c883-21f3-4e0c-a471-d1db2d15e4e6
- C:\ProgramData\Microsoft\Windows\WER\ReportArchive\8ef4ef68-34be-4bf7-b527-30f317c0eba0
- C:\ProgramData\Microsoft\Windows\WER\ReportArchive\c94a7905-865c-4d2d-9c9f-066f044285eb
- C:\ProgramData\Microsoft\Windows\WER\ReportQueue\35153d87-9664-4322-a934-a33d12c53b6b
- C:\ProgramData\Microsoft\Windows\WER\Temp\WER.2539f4d0-93c0-4ecf-bbe8-7752e679d270.tmp.csv
- C:\ProgramData\Microsoft\Windows\WER\Temp\WER.5566de91-2435-4336-b6ae-44affa44ab77.tmp.dmp
- C:\ProgramData\Microsoft\Windows\WER\Temp\WER.5dcca86e-8826-4c44-9a66-9d67069a9ae5.tmp.WERInternalMetadata.xml
- C:\ProgramData\Microsoft\Windows\WER\Temp\WER.6710769c-dfe8-4ce7-8ec4-cc7561f1a0fb.tmp.csv
- C:\ProgramData\Microsoft\Windows\WER\Temp\WER.93eccd66-13a7-4f6f-91a4-f62c269ca957.tmp.WERInternalMetadata.xml
- \Sessions\1\BaseNamedObjects\Local\WERReportingForProcess4556
- \Sessions\1\BaseNamedObjects\InventorySynchronizationInventoryApplicationFileMutex6460
- \Sessions\1\BaseNamedObjects\Global\d8eeffc4-1feb-47d8-b4d4-fabeeb0b2955
- \Sessions\1\BaseNamedObjects\Local\WERReportingForProcess6944
- \Sessions\1\BaseNamedObjects\InventorySynchronizationInventoryApplicationFileMutex6696
Files this sample writes at runtime
This file drops 8 children at runtime. None are currently flagged malicious in our cache.
- 70069d2bb8b044795d5c…c4b012Never scannednever seen before
- 0fd16de21315e5ab65ac…0552c0Never scannednever seen before
- d4f14d641d89b5e08f37…ed70e8Never scannednever seen before
- 1a405367e0519feb83e8…2bc75fNever scannednever seen before
- 02bf25d5edd282bbd8a5…724c06Never scannednever seen before
- 22c1e764f85aaf58130e…1403daNever scannednever seen before
- 91349c4fbe07d78c4397…039a53Never scannednever seen before
- f7f4df66395232eeb0e9…50434fNever scannednever seen before
Detection & Forensics
Consensus, attribution, signatures, code structure, prevalence, and identity.
Evidence integrity
Chain of custody for the facts preserved in this report.
- 0rule hits recorded
- 1 / 75engines flagged
- 95sources in submission history
Why these facts are shown
Each statement identifies whether it was directly recorded or derived from saved scan facts.
- 01
1 of 75 antivirus engines flagged the file, including Cynet.
Verdict inputView chapterProvenanceObservedSourceAntivirus analysisObserved at - 02
The hash has been submitted 133 times from 95 sources.
ProvenanceDerivedSourceSaved report factsObserved at - 03
Scanned file: winmm.dll — c2b1436e008af560016b0fc3659bb714c4a977f8f342e020e68f54747267edf5
ProvenanceObservedSourceUploaded fileObserved at - 04
Observed process — "C:\Windows\sysnative\rundll32.exe" "C:\Users\<USER>\Desktop\winmm.dll",#1
ProvenanceObservedSourceIsolated runtime analysisObserved at - 05
Observed process — C:\Windows\System32\loaddll64.exe loaddll64.exe "C:\Users\user\Desktop\winmm.dll"
ProvenanceObservedSourceIsolated runtime analysisObserved at - 06
File written: 597fea61-0f2f-4f35-be93-bda8c9b3cd7a — C:\ProgramData\Microsoft\Windows\WER\ReportArchive\597fea61-0f2f-4f35-be93-bda8c9b3cd7a
ProvenanceObservedSourceIsolated runtime analysisObserved at - 07
File written: 8115c883-21f3-4e0c-a471-d1db2d15e4e6 — C:\ProgramData\Microsoft\Windows\WER\ReportArchive\8115c883-21f3-4e0c-a471-d1db2d15e4e6
ProvenanceObservedSourceIsolated runtime analysisObserved at
Detection sources at a glance
The available sources did not agree on a named threat category.
MalwareBazaar, YARAify, and CIRCL hashlookup completed and returned no entries for this hash.
YARA rules
No matchesThe rule pass completed without a saved public match.
1 of 75 engines flagged this file
View all 75 engine results
Section entropy & packers
No high-entropy executable section or known packer signature was detected. Data and resource sections can still have high entropy without indicating packed code.
How widely this file has been seen
Moderate prevalence — neither rare nor common. No strong prior applies.
Fingerprint and provenance
- File name
- winmm.dll
- Format
- Win32 DLL
- Code signing
- No verified publisher
- Size
- 1.1 MB
- Last analyzed
- Oct 2, 2026, 7:35 PM UTC
c2b1436e008af560016b0fc3659bb714c4a977f8f342e020e68f54747267edf5Safety & FAQ
Complete recovery guidance and answers for the next decision.
What to do now
This file appears low risk based on the evidence available now.
- Recovery step 01
Use it only as part of software obtained from the developer's official site or another source you independently trust.
- Recovery step 02
A clean result reduces known risk, but it cannot guarantee that every new or targeted threat has been detected.
- Recovery step 03
Keep your antivirus and Windows updates switched on so you stay protected.
Safety FAQ
Direct answers grounded in the saved verdict and evidence in this report.
Is winmm.dll safe?
What is winmm.dll?
How many antivirus engines detected winmm.dll?
What is the SHA-256 hash of winmm.dll?
Is it safe to use winmm.dll?
How up to date is this analysis of winmm.dll?
Community
Member reviews and reports for this exact file hash.