Is 7zS.sfx.exe safe?
Mozilla-signed Firefox stub installer with zero engine detections and clean child/host results.
All 75 engines returned clean. The file is signed by Mozilla Corporation, a trusted publisher, and no malicious children or hosts were found. Sandbox activity matches typical installer behaviour.
36759542751a7cd0ae…946a75013546c0Recommended 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.
All 75 engines returned clean. The file is signed by Mozilla Corporation, a trusted publisher, and no malicious children or hosts were found. Sandbox activity matches typical installer behaviour.
Zero malicious detections across 75 engines, including 17 tier-1 engines, combined with verified Mozilla signing and no malicious dropped children or contacted hosts, strongly indicates a legitimate installer. The observed process-injection and LSASS activity are consistent with stub-installer unpacking and do not override the clean engine and signer evidence.
What We Detected
75 antivirus engines scanned the file; none flagged it malicious. The executable is signed and verified by Mozilla Corporation, a trusted publisher. Sandbox execution showed typical stub-installer behaviour: UPX unpacking, writing temporary setup files, and contacting Mozilla version-check endpoints.
Threat Behavior
Although the sandbox recorded T1055 (process injection) and LSASS access, these actions are expected during legitimate installer self-extraction and privilege elevation. No malicious child files were dropped and the single inspected external host had no prior malicious reputation.
What To Do Now
Keep Windows Defender and other endpoint protection enabled. If the file was obtained from the official Mozilla site or a trusted mirror, it can be executed. Should any unexpected behaviour occur, submit the sample for further analysis.
Where this verdict could be wrong1 caveat
- Sandbox observed LSASS access and direct-IP traffic, but these are common in legitimate stub installers and no complete contacted-host reputation result was available reputation was found.
These are the assessment's weak points. If you believe one applies to your file, report the verdict and we'll re-review it.
- Mozilla Corporation trusted publisher signature
- Zero engine detections across 75 scanners
- No malicious dropped children
- no complete contacted-host reputation result was available
The file can be considered safe; continue normal security practices and keep protection software enabled.
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
Partial1 of 3 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
- 10MITRE ATT&CK techniques
- 11spawned processes
- 3network contacts
- 26filesystem & 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
7zS.sfx.exe
36759542751a7cd0aeb6e47530db9cb084c108c97369d49665946a75013546c0
01Uploaded file
Processes
Runtime execution
- ProcessObserved
Observed process
"C:\Users\<USER>\Desktop\Firefox Installer.exe"
02Isolated runtime analysis - ProcessObserved
Observed process
.\setup-stub.exe
03Isolated runtime analysis - +1 more recorded observation in Analyst mode
Files
Created or changed
- Written fileObserved
setup-stub.exe
C:\Users\<USER>\AppData\Local\Temp\7zS4A5080F0\setup-stub.exe
04Isolated runtime analysis - Written fileObserved
postSigningData
C:\Users\<USER>\AppData\Local\Temp\7zS4A5080F0\postSigningData
05Isolated runtime analysis - +1 more recorded observation in Analyst mode
Network
Hosts contacted
- Contacted hostObserved
18.238.171.61
Contact observed during runtime.
06Isolated runtime analysis - Contacted hostObserved
162.159.36.2
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.
- 18.238.171.61
- 162.159.36.2
- https://product-details.mozilla.org/1.0/firefox_versions.json
- C:\Users\<USER>\AppData\Local\Temp\7zS4A5080F0\setup-stub.exe
- C:\Users\<USER>\AppData\Local\Temp\7zS4A5080F0\postSigningData
- C:\Users\<USER>\AppData\Local\Temp\nspC9AA.tmp\System.dll
- C:\Users\<USER>\AppData\Local\Temp\nspC9AA.tmp\UAC.dll
- C:\Windows\ServiceProfiles\LocalService\AppData\Local\FontCache\Fonts\Download-1.tmp
- C:\Users\<USER>\AppData\Local\Temp\nse90F6.tmp
- C:\Users\<USER>\AppData\Local\Temp\nsk9117.tmp
- C:\Program Files\Mozilla Firefox\nsc90C0.tmp
- C:\Program Files\Mozilla Firefox\nsc90C1.tmp
- C:\Program Files\Mozilla Firefox\nsm90AE.tmp
- MozillaMozilla FirefoxStubInstallerMutex
- Local\SessionImmersiveColorMutex
- \Sessions\1\BaseNamedObjects\MozillaMozilla FirefoxStubInstallerMutex
Files this sample writes at runtime
This file drops 8 children at runtime. None are currently flagged malicious in our cache.
- 50def86f44839e6fbef8…e5d6a3Never scannednever seen before
- b711c4f17690421c9dc8…701c04Never scannednever seen before
- ec6a56d981892bf251df…70338cNever scannednever seen before
- 7bf29d952ded94550678…8837feNever scannednever seen before
- c299a0a71bf57eb24186…334a14Never scannednever seen before
- c6c413108539f141bea3…e2e2dfNever scannednever seen before
- d86446129e0c9aee0288…d67eafNever scannednever seen before
- 7da3182de713cdbfa901…9818d5Never 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
- 0 / 75engines flagged
- 6sources 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 file has a valid code signature from Mozilla Corporation.
ProvenanceObservedSourceCode-signing metadataObserved at - 03
1 high-confidence signature or behavior rule matched this file.
Verdict inputView chapterProvenanceDerivedSourceSignature and behavior rulesObserved at - 04
Scanned file: 7zS.sfx.exe — 36759542751a7cd0aeb6e47530db9cb084c108c97369d49665946a75013546c0
ProvenanceObservedSourceUploaded fileObserved at - 05
Observed process — "C:\Users\<USER>\Desktop\Firefox Installer.exe"
ProvenanceObservedSourceIsolated runtime analysisObserved at - 06
Observed process — .\setup-stub.exe
ProvenanceObservedSourceIsolated runtime analysisObserved at - 07
File written: setup-stub.exe — C:\Users\<USER>\AppData\Local\Temp\7zS4A5080F0\setup-stub.exe
ProvenanceObservedSourceIsolated runtime analysisObserved at - 08
File written: postSigningData — C:\Users\<USER>\AppData\Local\Temp\7zS4A5080F0\postSigningData
ProvenanceObservedSourceIsolated runtime analysisObserved at - 09
Contacted host: 18.238.171.61 — Contact observed during runtime.
ProvenanceObservedSourceIsolated runtime analysisObserved at - 10
Contacted host: 162.159.36.2 — Contact observed during runtime.
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.
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.
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.
Evidence18.238.171.61 · 162.159.36.2
0 of 75 engines flagged this file
View all 75 engine results
Section entropy & packers
Executable sections have high entropy (7.2+) — the code is compressed or encrypted and only decrypted at runtime. Classic packing behaviour.
How widely this file has been seen
Moderate prevalence — neither rare nor common. No strong prior applies.
Fingerprint and provenance
- File name
- 7zS.sfx.exe
- Format
- Win32 EXE
- Code signing
- Signature valid: Mozilla Corporation
- Size
- 492.5 KB
- Last analyzed
- Aug 21, 2026, 1:38 PM UTC
36759542751a7cd0aeb6e47530db9cb084c108c97369d49665946a75013546c0Safety & 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 7zS.sfx.exe safe?
What is 7zS.sfx.exe?
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Is 7zS.sfx.exe digitally signed?
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Community
Member reviews and reports for this exact file hash.