Is winmm.dll safe?
Four tier-1 engines plus two more on the same family flag this unsigned 110-day-old DLL.
20 of 75 engines detect the file, four of them tier-1, converging on the Malgent family. The DLL is unsigned, shows medium prevalence, and carries no sandbox or network evidence.
063a8d5e57cd760a8e…614e23dc1a2568Recommended next actions
Before using
Do not use it. Quarantine this component with your antivirus, then repair or reinstall the parent software from its official source. Do not delete or replace the component manually.
If you already used it
Disconnect from the internet, start a full or offline antivirus scan, then secure important accounts from a clean device.
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.
20 of 75 engines detect the file, four of them tier-1, converging on the Malgent family. The DLL is unsigned, shows medium prevalence, and carries no sandbox or network evidence.
The combination of four tier-1 detections and a two-engine tier-1 family consensus on Malgent outweighs the lack of runtime or network indicators. The file is unsigned despite being a system-named DLL, which is atypical for legitimate Windows components. Medium prevalence and 110-day history reduce the chance of a brand-new false positive. The single community annotation also labels it malicious with high confidence.
What We Detected
20 of 75 engines flag the sample; Ikarus, Microsoft, Sophos and TrendMicro-HouseCall are tier-1. Two tier-1 engines agree on the Malgent family. The file is an unsigned 502 kB Win32 DLL submitted 110 days ago with medium prevalence.
Threat Behavior
Sandbox execution produced ambient techniques only; no malicious verdict, no contacted domains, and no dropped children. The filename winmm.dll matches a legitimate Windows library, yet the binary carries no signature.
What To Do Now
Do not load or execute the file. Keep endpoint protection enabled and remove the DLL from any location where it could be side-loaded by rundll32 or other processes.
Where this verdict could be wrong1 caveat
- behaviour.hasMaliciousSandboxVerdict=false and no contacted domains or dropped children observed.
These are the assessment's weak points. If you believe one applies to your file, report the verdict and we'll re-review it.
- No malicious sandbox verdict
- No contacted malicious hosts recorded
- Unsigned system-named DLL
- Tier-1 consensus on Malgent family
- Medium prevalence but persistent detections
Treat the file as malicious and block or delete it; maintain current antivirus coverage.
Coverage & freshness
Complete means the check returned a usable result. It does not mean the file is safe.
Antivirus
Complete20 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
- 12MITRE ATT&CK techniques
- 9spawned processes
- 0network contacts
- 1filesystem & mutex artifacts
What this file does
Observed actions and their security significance
High concern: Manipulated how the operating system loads code, which can redirect execution.
Moderate concern: Contained obfuscated or packed code that makes inspection harder.
Moderate concern: Runs hidden system commands (script or shell).
Moderate concern: Scans through your files and folders.
Note: Reads your Windows user-account details.
Note: Listed running processes; both legitimate software and malware may do this.
Note: Collects details about your system.
These are observed capabilities from an isolated analysis. A technique does not prove malicious intent on its own, and the file never ran on your device.
Threat context
How trojans work
A trojan disguises itself as something useful or harmless to trick you into running it. Once open, it does its real job in the background — anything from stealing data to opening a back door or downloading more malware.
Bottom line:The disguise is the whole trick, so a trustworthy-looking name or icon means nothing.
Attack story
Runtime observations grouped by analysis stage. Arrows organize the stages; they do not claim chronology or causality.
Input file
The submitted object
- FileObserved
winmm.dll
063a8d5e57cd760a8eafb3573146cc97e18180412a5a0efc23614e23dc1a2568
01Uploaded file
Processes
Runtime execution
- ProcessObserved
Observed process
"C:\Windows\sysnative\rundll32.exe" "C:\Users\<USER>\Desktop\init.dll",#1
02Isolated runtime analysis - ProcessObserved
Observed process
rundll32.exe
03Isolated runtime analysis - +1 more recorded observation in Analyst mode
Files
Created or changed
- Written fileObserved
Connect
\Device\ConDrv\\Connect
04Isolated runtime analysis
4 recorded facts from one runtime window. Every fact remains independently traceable in Analyst mode.
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.
- \Device\ConDrv\\Connect
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
- 20 / 75engines flagged
- 3,415sources in submission history
Why these facts are shown
Each statement identifies whether it was directly recorded or derived from saved scan facts.
- 01
20 of 75 antivirus engines flagged the file, including alibabacloud and CTX.
Verdict inputView chapterProvenanceObservedSourceAntivirus analysisObserved at - 02
The hash has been submitted 5,704 times from 3,415 sources.
ProvenanceDerivedSourceSaved report factsObserved at - 03
Scanned file: winmm.dll — 063a8d5e57cd760a8eafb3573146cc97e18180412a5a0efc23614e23dc1a2568
ProvenanceObservedSourceUploaded fileObserved at - 04
Observed process — "C:\Windows\sysnative\rundll32.exe" "C:\Users\<USER>\Desktop\init.dll",#1
ProvenanceObservedSourceIsolated runtime analysisObserved at - 05
Observed process — rundll32.exe
ProvenanceObservedSourceIsolated runtime analysisObserved at - 06
File written: Connect — \Device\ConDrv\\Connect
ProvenanceObservedSourceIsolated runtime analysisObserved at
Detection sources at a glance
Category: generic-trojan
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.
20 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
- 490.5 KB
- Last analyzed
- Aug 29, 2026, 2:45 PM UTC
063a8d5e57cd760a8eafb3573146cc97e18180412a5a0efc23614e23dc1a2568Safety & FAQ
Complete recovery guidance and answers for the next decision.
What to do now
This file is dangerous. Treat it as harmful and remove it.
- Recovery step 01
Don't use this component. Quarantine this component with your antivirus, then repair or reinstall the parent software from its official source. Do not delete or replace the component manually.
- Recovery step 02
If you already used it, disconnect from the internet and start with a full antivirus scan or Microsoft Defender Offline scan. If compromise is suspected or the problem persists, use a reputable second-opinion scanner and follow incident-recovery or clean-reinstall guidance.
- Recovery step 03
If you typed any passwords while it was open, change them from a device you trust.
- Recovery step 04
Reinstall the parent software from the developer's official site instead of replacing this component by itself.
Safety FAQ
Direct answers grounded in the saved verdict and evidence in this report.
Is winmm.dll malware?
What is winmm.dll?
How many antivirus engines detected winmm.dll?
I already downloaded and used winmm.dll — what should I do?
How do I remove winmm.dll?
What kind of malware is winmm.dll?
What is the SHA-256 hash of winmm.dll?
How up to date is this analysis of winmm.dll?
Community
Member reviews and reports for this exact file hash.