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[Enhancement] PowerShell - Optimize Entropy Calculation, Add Normalized Entropy, Add Pipeline Benchmark#16707
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[Enhancement] PowerShell - Optimize Entropy Calculation, Add Normalized Entropy, Add Pipeline Benchmark#16707
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elasticmachine commentedDec 26, 2025
Pinging @elastic/sec-windows-platform (Team:Security-Windows Platform) |
elasticmachine commentedJan 4, 2026
Pinging @elastic/elastic-agent-data-plane (Team:Elastic-Agent-Data-Plane) |
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mauri870 approved these changesJan 5, 2026
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LGTM, but I'm not very proficient with PowerShell. The code looks fine, but it needs a deeper look from the Windows team.
| double normalizedEntropy = 0.0; | ||
| if (length > 1) { | ||
| double maxEntropy = Math.log((double) length) * invLog2; // max bits if every character is unique |
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I think the normalized entropy calculation looks good 👍
Few notes for posterity:
- For the line
double maxEntropy = Math.log((double) length) * invLog2; // max bits if every character is uniqueI think it makes sense to use length here. Typical normalized entropy calculations (like that for R/Posteriorref) would use something akin toseenCountinstead oflength. However, this is expecting the input to be more akin to categories whereaandaare equivalent regardless of their position in the script block. In our case, I think we want the position to mater as well, so each value is by definition unique makinglengththe correct number to use here (as is correctly done in the code). - The pre-output check
else if (normalizedEntropy > 1.0) normalizedEntropy = 1.0;I think is technically not necessary, as this should not occur. However, I think we should keep this check as it could catch floating point rounding issues without impacting the integrity of the data result (code is correct as is).
nfritts approved these changesJan 23, 2026
🚀 Benchmarks reportTo see the full report comment with |
elasticmachine commentedJan 23, 2026
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gogochan approved these changesJan 23, 2026
da83fd3 intomain 8 checks passed
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Package windows - 3.4.0 containing this change is available athttps://epr.elastic.co/package/windows/3.4.0/ |
jakubgalecki0 pushed a commit to jakubgalecki0/integrations that referenced this pull requestFeb 19, 2026
…ed Entropy, Add Pipeline Benchmark (elastic#16707)* [Enhancement] PowerShell - Optimize Entropy Calculation, Add Normalized Entropy, Add Pipeline Benchmark* Update test-powershell-operational-events.json-expected.json* Update changelog.yml* rename benchmark file
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documentationImprovements or additions to documentation. Applied to PRs that modify *.md files. enhancementNew feature or request Integration:windowsWindows Team:Elastic-Agent-Data-PlaneAgent Data Plane team [elastic/elastic-agent-data-plane] Team:Security-Windows PlatformSecurity Windows Platform team [elastic/sec-windows-platform]
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Proposed commit message
Summary
Related issue:
This PR:
powershell.file.script_block_entropy_normalized= entropy_bits / log2(script_block_length) (0–1).Old pipeline:
Improved pipeline:
Complete benchmark output
Old:
Improved:
Checklist
changelog.ymlfile.