Is dotNetFx40_Full_setup.exe safe?
Microsoft-signed .NET Framework 4.0 installer with zero engine detections and strong historical signer reputation.
Zero of 75 engines flagged the file. It is signed by Microsoft Corporation, matches a trusted-publisher record, and shows 4 of 5 similar hashes previously rated safe under the same signer. The file is a common, old .NET redistributable installer.
fa1afff978325f8818…03656d93104425Recommended next actions
Before installing
Install it only when it came from the developer's official site or an official app store.
If you already installed 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.
Zero of 75 engines flagged the file. It is signed by Microsoft Corporation, matches a trusted-publisher record, and shows 4 of 5 similar hashes previously rated safe under the same signer. The file is a common, old .NET redistributable installer.
The complete absence of malicious detections across 75 engines, including 17 tier-1 engines, combined with verified Microsoft code-signing, places the sample firmly in the benign-signed-installer pattern. Historical signer data shows 8/9 prior samples rated safe, and four of five similar-hash matches under the same signer also returned safe verdicts with the same reason code. Prevalence data (common_old, nearly 90 k submissions) further supports legitimate commodity software. Sandbox artefacts that triggered heuristic rules are consistent with a .NET bootstrapper touching LSASS and system services during installation; no malicious child files or sandbox verdicts were recorded.
What We Detected
75-engine scan returned zero malicious or suspicious labels. The executable is signed by Microsoft Corporation with a verified certificate issued 19 March 2010. Our trusted-publisher list explicitly includes Microsoft, and the file matches the expected .NET Framework 4.0 redistributable (dotNetFx40_Full_setup.exe).
Threat Behavior
One sandbox recorded typical installer behaviour: extraction of bitmap resources, creation of temporary files, and service-process interaction. Four MITRE techniques flagged by heuristics (T1005, T1055, T1543.003, T1562.001) map to expected bootstrapper actions rather than attacker tradecraft. no complete contacted-host reputation result was available, IPs, or child processes were observed.
What To Do Now
The file can be executed or distributed without elevated concern. Keep Windows Defender and other endpoint protection enabled; no additional action is required.
Where this verdict could be wrong2 caveats
- signerStats shows 1/9 malicious historical sample for Microsoft Corporation — single outlier against 8/9 safe.
- triggeredHeuristics fired 'MalwareTips.Synth.CredentialDumper' and 'MalwareTips.Synth.ProcessInjection' on LSASS and svchost activity — sandbox artefacts from legitimate .NET installer bootstrapper.
These are the assessment's weak points. If you believe one applies to your file, report the verdict and we'll re-review it.
- Microsoft Corporation code signature verified
- 0/75 engines flagged malicious
- common_old prevalence with nearly 90 k submissions
- 4 of 5 similar signer-matched hashes previously rated safe
Treat as a legitimate Microsoft .NET Framework 4.0 installer; no further security action needed.
Coverage & freshness
Complete means the check returned a usable result. It does not mean the file is safe.
Antivirus
Complete0 of 75 engines flagged the file.
Sandbox
Complete1 isolated runtime environment contributed observations.
Network
Partial20 runtime contacts were observed without a completed reputation cross-check.
YARA
Complete7 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
- 23MITRE ATT&CK techniques
- 15spawned processes
- 20network contacts
- 40filesystem & mutex artifacts
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
dotNetFx40_Full_setup.exe
fa1afff978325f8818ce3a559d67a58297d9154674de7fd8eb03656d93104425
01Uploaded file
Processes
Runtime execution
- ProcessObserved
Observed process
"C:\Users\<USER>\Desktop\executable.exe"
02Isolated runtime analysis - ProcessObserved
Observed process
C:\64a030f465b63e86a21d3070bd\\Setup.exe /x86 /x64 /ia64 /web
03Isolated runtime analysis - +1 more recorded observation in Analyst mode
Files
Created or changed
- Written fileObserved
dd_executable_decompression_log.txt
C:\Users\<USER>\AppData\Local\Temp\dd_executable_decompression_log.txt
04Isolated runtime analysis - Written fileObserved
header.bmp
C:\64a030f465b63e86a21d3070bd\header.bmp
05Isolated runtime analysis - +1 more recorded observation in Analyst mode
Network
Hosts contacted
- Contacted hostObserved
23.59.190.208
Contact observed during runtime.
06Isolated runtime analysis - Contacted hostObserved
a83f:8110:5766:7048:dc3d:45a4:1e57:1947
Contact observed during runtime.
07Isolated runtime analysis - +1 more recorded observation in Analyst mode
7 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.
- 23.59.190.208
- a83f:8110:5766:7048:dc3d:45a4:1e57:1947
- 192.168.0.85
- 8.240.39.126
- 192.168.0.11
- 72.21.81.240
- 13.107.4.50
- a83f:8110:0:0:700:700:2800:4000
- 23.216.147.64
- a83f:8110:89:8424:3001:0:488d:152d
- C:\Users\<USER>\AppData\Local\Temp\dd_executable_decompression_log.txt
- C:\64a030f465b63e86a21d3070bd\header.bmp
- C:\64a030f465b63e86a21d3070bd\SplashScreen.bmp
- C:\64a030f465b63e86a21d3070bd\watermark.bmp
- C:\64a030f465b63e86a21d3070bd\DisplayIcon.ico
- C:\Users\<USER>\AppData\Local\Temp\HFID92A.tmp.html
- C:\Users\<USER>\AppData\Local\Temp\Setup_20260118_035519045.html
- %USERPROFILE%\AppData\Local\Temp\HFI7CC.tmp.html
- %USERPROFILE%\AppData\Local\Temp\HFI2537.tmp.html
- C:\Windows\ServiceProfiles\LocalService\AppData\Roaming\Microsoft\Crypto\Keys\de7cf8a7901d2ad13e5c67c29e5d1662_cbbb49d6-b7ff-44ca-aba5-8a5e250d4d42
- Global\NetFxSetupMutex
- Local\Shell.CMruPidlList
- CTF.LBES.MutexDefaultS-1-5-21-1482476501-1645522239-1417001333-500
- CTF.Compart.MutexDefaultS-1-5-21-1482476501-1645522239-1417001333-500
- CTF.Asm.MutexDefaultS-1-5-21-1482476501-1645522239-1417001333-500
Files this sample writes at runtime
This file drops 10 children at runtime. None are currently flagged malicious in our cache.
- d273460aa4d42f0b5764…55d8beNever scannednever seen before
- 19abcedf93d790e19fb3…9943e4Never scannednever seen before
- 02a7fe932029c6fa24d1…b3d1f6Never scannednever seen before
- ae041c8764f56fd89277…71c6e5Never scannednever seen before
- ab18374b3aab10e5979e…e2d33aNever scannednever seen before
- 5fb03593071a99c7b380…19723cNever scannednever seen before
- 7e682bdf51fac1b3991e…70888aNever scannednever seen before
- 8d82ff7970c9a67da813…c698abNever scannednever seen before
- 6b67c8a77c1a637b7273…3ffa66Never scannednever seen before
- 61d8339e89a9e48f8ae2…47c8a3Never 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.
- 7rule hits recorded
- 0 / 75engines flagged
- 3,687sources in submission history
Why these facts are shown
Each statement identifies whether it was directly recorded or derived from saved scan facts.
- 01
0 of 75 antivirus engines flagged the file.
Verdict inputView chapterProvenanceObservedSourceAntivirus analysisObserved at - 02
The hash appears in a known-software reference database.
Verdict inputView chapterProvenanceObservedSourceReference software databaseObserved at - 03
The hash has a long, established submission history across 3,687 sources.
Verdict inputView chapterProvenanceDerivedSourceSubmission historyObserved at - 04
Scanned file: dotNetFx40_Full_setup.exe — fa1afff978325f8818ce3a559d67a58297d9154674de7fd8eb03656d93104425
ProvenanceObservedSourceUploaded fileObserved at - 05
Observed process — "C:\Users\<USER>\Desktop\executable.exe"
ProvenanceObservedSourceIsolated runtime analysisObserved at - 06
Observed process — C:\64a030f465b63e86a21d3070bd\\Setup.exe /x86 /x64 /ia64 /web
ProvenanceObservedSourceIsolated runtime analysisObserved at - 07
File written: dd_executable_decompression_log.txt — C:\Users\<USER>\AppData\Local\Temp\dd_executable_decompression_log.txt
ProvenanceObservedSourceIsolated runtime analysisObserved at - 08
File written: header.bmp — C:\64a030f465b63e86a21d3070bd\header.bmp
ProvenanceObservedSourceIsolated runtime analysisObserved at - 09
Contacted host: 23.59.190.208 — Contact observed during runtime.
ProvenanceObservedSourceIsolated runtime analysisObserved at - 10
Contacted host: a83f:8110:5766:7048:dc3d:45a4:1e57:1947 — 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.
- DebuggerCheck__API
- NET
- PE_Digital_Certificate
- SHA512_Constants
The saved runtime evidence maps this activity to MITRE T1055 (Process Injection). The mapping supports possible process injection, but it does not prove the exact injection method or the operator's intent.
EvidenceC:\Windows\System32\svchost.exe -k NetworkService -pSandbox observed process activity targeting LSASS (Windows credential store). Legitimate software has no business reading LSASS memory — this is Mimikatz-shape behaviour.
EvidenceC:\Windows\system32\lsass.exeThe sample contacted an external IP address directly and no application domain was recorded. Direct-IP traffic also occurs in legitimate installers and infrastructure, so this is supporting context only and requires corroboration from host reputation and other runtime evidence.
Evidence23.59.190.208 · a83f:8110:5766:7048:dc3d:45a4:1e57:1947 · 8.240.39.126
0 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
Widely seen in the wild for a long time. High prior this is legitimate; isolated detections on common-old files are usually false positives.
Fingerprint and provenance
- File name
- dotNetFx40_Full_setup.exe
- Format
- Win32 EXE
- Code signing
- Signature valid: Microsoft Corporation
- Size
- 868.6 KB
- Last analyzed
- Aug 26, 2026, 7:53 PM UTC
fa1afff978325f8818ce3a559d67a58297d9154674de7fd8eb03656d93104425Safety & 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
Install it only when it came from the developer's official site or an official app store.
- 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 dotNetFx40_Full_setup.exe safe?
What is dotNetFx40_Full_setup.exe?
How many antivirus engines detected dotNetFx40_Full_setup.exe?
Is dotNetFx40_Full_setup.exe digitally signed?
What is the SHA-256 hash of dotNetFx40_Full_setup.exe?
Is it safe to install dotNetFx40_Full_setup.exe?
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Community
Member reviews and reports for this exact file hash.