Is NemuDownloader.exe safe?
Only 1 of 75 engines raised a riskware label, while verified Netease signing, prior matching builds, and observed execution strongly support a false positive.
The executable is verified as signed by Netease Interactive Entertainment Pte. Ltd., and only 1 of 75 engines raised a PUA-style riskware label. A completed sandbox run found no offensive techniques or malicious verdict, while two matching signed builds were previously assessed as benign; the anti-VM YARA match remains a caution.
2314b74a445694ce39…6e03bc226fe91bRecommended next actions
Before running
Run it only when it came from the developer's official site or another source you independently trust.
If you already ran 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.
The executable is verified as signed by Netease Interactive Entertainment Pte. Ltd., and only 1 of 75 engines raised a PUA-style riskware label. A completed sandbox run found no offensive techniques or malicious verdict, while two matching signed builds were previously assessed as benign; the anti-VM YARA match remains a caution.
Only NANO-Antivirus flagged the sample among 75 engines, using a riskware/PUA label rather than a corroborated malware family, while all 17 reporting tier-1 engines were silent. The signature verifies to Netease Interactive Entertainment Pte. Ltd., and both historical samples associated with this signer were assessed as benign. A completed sandbox run recorded ordinary installer and system-discovery activity, no offensive-only techniques, and no malicious runtime verdict. Ten dropped children produced no known malicious child, and the reputation check found no known-malicious or suspicious entries among all three contacted domains, although the observed IP addresses lacked documented coverage. Two matched signed builds sharing this imphash also received prior benign assessments. The two YARA matches and packed downloader profile warrant caution, but they do not outweigh the broader independent evidence.
What We Detected
Only 1 of 75 antivirus engines flagged this executable. NANO-Antivirus used the label Riskware.Win32.Fragtor.ljrxgl, while no tier-1 engine detected it and no tier-1 family consensus formed. The executable has a verified signature from Netease Interactive Entertainment Pte. Ltd.; two historical samples for that signer and two matching signed builds sharing the imphash were previously assessed as benign.
Threat Behavior
One completed sandbox run observed downloader-style network activity and common installer or system-discovery techniques, but no offensive-only technique and no malicious sandbox verdict. Ten dropped children were inspected without identifying a malicious child. All three contacted domains were checked without a known-malicious or suspicious result, though the three observed IP addresses did not have documented reputation coverage. Two community YARA rules matched, including an anti-VM rule, and the PE appears packed; these are cautionary signals but are not independently conclusive.
What To Do Now
Use the file only if it came from Netease or the official MuMu distribution channel and Windows confirms the same valid signer. Keep endpoint protection enabled, and obtain a fresh official copy if the download source or signature differs.
Where this verdict could be wrong4 caveats
- YARAify matched 2 rules, including 'TH_AntiVM_MassHunt_Win_Malware_2026_CYFARE', which alleges anti-VM or anti-sandbox traits and prevents treating the evidence as entirely clean.
- peAnalysis.likelyPacked=true and MalwareTips.Synth.DropperNetworkProfile fired because the signed executable combined packing, network activity, and one engine flag.
- signing.signerStats contains only 2 historical samples and autoTrusted=false, so the clean signer history is supportive but not yet extensive.
- The contactedHosts block covered the three domains but did not document reputation results for the three observed IP addresses.
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 flagged the file, with tier1Malicious=0
- Verified signature from Netease Interactive Entertainment Pte. Ltd.
- signing.signerStats shows 2/2 safe samples
- similarHashes shows 2/2 prior safe signed matches
- No malicious sandbox verdict or malicious dropped child
- externalIntel.yaraify.ruleCount=2, including an anti-VM or anti-sandbox rule
- peAnalysis.likelyPacked=true
- MalwareTips.Synth.DropperNetworkProfile fired
- NANO-Antivirus reported Riskware.Win32.Fragtor.ljrxgl
- signing.signerStats is limited to 2 samples
Confirm the valid Netease Interactive Entertainment Pte. Ltd. signature and use a copy obtained from the official MuMu or Netease channel. Keep endpoint protection enabled and replace the file if its source is uncertain.
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
Partial3 of 6 contacted hosts were cross-checked; coverage is incomplete.
YARA
Complete3 signature or behavior rules matched.
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
- 8MITRE ATT&CK techniques
- 7spawned processes
- 6network contacts
- 19filesystem & 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.
- api.mumuglobal.com
- zsos-api.ntes53.netease.com
- cl-glcb907925.gcdn.co
- 8.8.8.8
- 34.36.47.246
- 162.159.36.2
- Software\NemuServer\uuid
- Software\NemuServer\channel
- HKEY_USERS\S-1-5-21-4270068108-2931534202-3907561125-1001\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.exe\OpenWithProgids\exefile
- C:\Users\Virtual\AppData\Local\Temp\7z58A529D4\api-ms-win-crt-math-l1-1-0.dll
- C:\Users\Virtual\AppData\Local\Temp\winring0x64.cat
- C:\Users\Virtual\AppData\Local\Temp\WinRing0x64.sys
- C:\Users\Virtual\AppData\Local\Temp\7z58A529D4\api-ms-win-crt-conio-l1-1-0.dll
- C:\Users\Virtual\AppData\Local\Temp\7z58A529D4\skin.zip
- C:\Users\Virtual\AppData\Local\NemuServer\.sentry-native\3475a430-3dc2-44f9-08a1-92460018b66d.run\session.json
- C:\Users\<USER>\AppData\Local\NemuServer\.sentry-native\b2151888-78d4-40d8-d2c9-89eeac9c363b.run\session.json
- ColaBoxChecker:config
- nemu-downloader-run-mutex
Files this sample writes at runtime
This file drops 10 children at runtime. None are currently flagged malicious in our cache.
- fc0551de11b310dfd8f3…66f148Never scannednever seen before
- 6d5881719e9599bf10a4…84ed3eNever scannednever seen before
- df6bed7bcccaf7298133…62d356Never scannednever seen before
- 104a76b41cbd9a945dba…20f728Never scannednever seen before
- 65aa91ee18b46603a554…2d6941Never scannednever seen before
- 8acd9e63a83f2facfc68…7d407fNever scannednever seen before
- e7272ff3b00508732896…d48156Never scannednever seen before
- 6ee46c6b6727eb77bcbc…58844eNever scannednever seen before
- 5f476627a904b182d9b3…5b3a8bNever scannednever seen before
- e087f611b3659151dfb6…40632dNever 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.
- 3rule hits recorded
- 1 / 75engines flagged
- 883sources in submission history
Why these facts are shown
Each statement identifies whether it was directly recorded or derived from saved scan facts.
- 01
The file has a valid code signature from Netease Interactive Entertainment Pte. Ltd..
ProvenanceObservedSourceCode-signing metadataObserved at - 02
3 high-confidence signature or behavior rules matched this file.
Verdict inputView chapterProvenanceDerivedSourceSignature and behavior rulesObserved at - 03
1 of 75 antivirus engines flagged the file, including NANO-Antivirus.
Verdict inputView chapterProvenanceObservedSourceAntivirus analysisObserved at - 04
Scanned file: NemuDownloader.exe — 2314b74a445694ce399e8e09c3e0d0eaba54341e252fd89bc76e03bc226fe91b
ProvenanceObservedSourceUploaded fileObserved at - 05
Observed process — tmphzmaB3.exe
ProvenanceObservedSourceIsolated runtime analysisObserved at - 06
Observed process — nemu-downloader.exe
ProvenanceObservedSourceIsolated runtime analysisObserved at - 07
File written: api-ms-win-crt-math-l1-1-0.dll — C:\Users\Virtual\AppData\Local\Temp\7z58A529D4\api-ms-win-crt-math-l1-1-0.dll
ProvenanceObservedSourceIsolated runtime analysisObserved at - 08
File written: winring0x64.cat — C:\Users\Virtual\AppData\Local\Temp\winring0x64.cat
ProvenanceObservedSourceIsolated runtime analysisObserved at - 09
Contacted host: api.mumuglobal.com — Contact observed during runtime.
ProvenanceObservedSourceIsolated runtime analysisObserved at - 10
Contacted host: zsos-api.ntes53.netease.com — Contact observed during runtime.
ProvenanceObservedSourceIsolated runtime analysisObserved at
Detection sources at a glance
The available sources did not agree on a named threat category.
One or more independent reference databases matched this hash.
Signatures and behavior heuristics
A community signature or high-severity behavioral heuristic matched. Signatures identify known patterns; heuristics are strong leads but are not proof on their own.
- PE_Digital_Certificate
- TH_AntiVM_MassHunt_Win_Malware_2026_CYFARE
1 of 75 engines flagged this file
View all 75 engine results
Section entropy & packers
A known packer signature (UPX / Themida / VMProtect / etc.) matched this file. Packers aren't malicious on their own, but most malware uses them.
Packers compress or encrypt the executable and only unpack it at runtime. Legitimate commercial software uses them too — but if the file is also unsigned and rare, it's a strong malware signal.
How widely this file has been seen
Moderate prevalence — neither rare nor common. No strong prior applies.
Fingerprint and provenance
- File name
- NemuDownloader.exe
- Format
- Win32 EXE
- Code signing
- Signature valid: Netease Interactive Entertainment Pte. Ltd.
- Size
- 5.8 MB
- Last analyzed
- Oct 4, 2026, 9:44 PM UTC
2314b74a445694ce399e8e09c3e0d0eaba54341e252fd89bc76e03bc226fe91bSafety & 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
Run it only when it came 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 NemuDownloader.exe safe?
What is NemuDownloader.exe?
How many antivirus engines detected NemuDownloader.exe?
Is NemuDownloader.exe digitally signed?
What is the SHA-256 hash of NemuDownloader.exe?
Is it safe to run NemuDownloader.exe?
How up to date is this analysis of NemuDownloader.exe?
Community
Member reviews and reports for this exact file hash.