{
  "synthetic": true,
  "date": "2026-10-05",
  "articleUrl": "https://toolpipo.com/articles/zip-before-extract-safety-test/",
  "toolUrl": "https://toolpipo.com/tools/zip-safety-checker/",
  "checkerSha256": "689a71611c4b68ab8ab9403fa870694dc2e19b969705806cdd962c6b1c792fd4",
  "library": "fflate 0.8.3",
  "method": "analyzeBytes with the published checker; every unzip filter returns false",
  "filesystemExtraction": false,
  "contentInflation": false,
  "nestedArchivesRecursivelyRead": false,
  "malwareAnalysis": false,
  "results": [
    {
      "id": "normal",
      "label": "通常の小さなZIP",
      "notDetermined": "安全性やファイル内容の正しさ",
      "fileName": "normal.zip",
      "zipSize": 872,
      "files": 3,
      "folders": 2,
      "totalUncompressed": 513,
      "expansionRatio": 0.588302752293578,
      "totalFindings": 0,
      "findings": [],
      "findingCounts": {},
      "suspiciousNames": [],
      "largest": [
        {
          "name": "documents/report.pdf",
          "compressedSize": 224,
          "originalSize": 414,
          "directory": false
        },
        {
          "name": "images/photo.png",
          "compressedSize": 67,
          "originalSize": 72,
          "directory": false
        },
        {
          "name": "documents/readme.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "extensionDistribution": [
        {
          "extension": "pdf",
          "count": 1,
          "originalSize": 414
        },
        {
          "extension": "png",
          "count": 1,
          "originalSize": 72
        },
        {
          "extension": "txt",
          "count": 1,
          "originalSize": 27
        }
      ],
      "entries": [
        {
          "name": "documents/",
          "compressedSize": 2,
          "originalSize": 0,
          "directory": true
        },
        {
          "name": "documents/readme.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        },
        {
          "name": "documents/report.pdf",
          "compressedSize": 224,
          "originalSize": 414,
          "directory": false
        },
        {
          "name": "images/",
          "compressedSize": 2,
          "originalSize": 0,
          "directory": true
        },
        {
          "name": "images/photo.png",
          "compressedSize": 67,
          "originalSize": 72,
          "directory": false
        }
      ],
      "sha256": "4f06b237211ce48239faa1cbcd34de7fe744d4843cc475c906aac99e6ce9eec4",
      "metadataFilter": {
        "examined": 5,
        "accepted": 0
      }
    },
    {
      "id": "executable-extension",
      "label": "実行形式の拡張子",
      "notDetermined": "実行内容・マルウェアの有無",
      "fileName": "executable-extension.zip",
      "zipSize": 270,
      "files": 2,
      "folders": 0,
      "totalUncompressed": 54,
      "expansionRatio": 0.2,
      "totalFindings": 1,
      "findings": [
        {
          "level": "要確認",
          "type": "executable",
          "label": "実行・script関連形式の候補",
          "name": "setup.exe",
          "detail": "拡張子 .exe に基づく分類であり、malwareとは判定していません。"
        }
      ],
      "findingCounts": {
        "executable": 1
      },
      "suspiciousNames": [
        "setup.exe"
      ],
      "largest": [
        {
          "name": "readme.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        },
        {
          "name": "setup.exe",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "extensionDistribution": [
        {
          "extension": "exe",
          "count": 1,
          "originalSize": 27
        },
        {
          "extension": "txt",
          "count": 1,
          "originalSize": 27
        }
      ],
      "entries": [
        {
          "name": "setup.exe",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        },
        {
          "name": "readme.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "sha256": "a84d93d42f1746d6fe81598861f83f94f40ffad0affb56b95dbed833557b5c3e",
      "metadataFilter": {
        "examined": 2,
        "accepted": 0
      }
    },
    {
      "id": "double-extension",
      "label": "二重拡張子",
      "notDetermined": "PDFや実行ファイルとしての内容",
      "fileName": "double-extension.zip",
      "zipSize": 157,
      "files": 1,
      "folders": 0,
      "totalUncompressed": 27,
      "expansionRatio": 0.17197452229299362,
      "totalFindings": 2,
      "findings": [
        {
          "level": "要確認",
          "type": "executable",
          "label": "実行・script関連形式の候補",
          "name": "invoice.pdf.exe",
          "detail": "拡張子 .exe に基づく分類であり、malwareとは判定していません。"
        },
        {
          "level": "要確認",
          "type": "double-extension",
          "label": "二重拡張子で実際の形式を見落とす可能性",
          "name": "invoice.pdf.exe",
          "detail": "最後の拡張子が実行・script関連形式です。"
        }
      ],
      "findingCounts": {
        "executable": 1,
        "double-extension": 1
      },
      "suspiciousNames": [
        "invoice.pdf.exe"
      ],
      "largest": [
        {
          "name": "invoice.pdf.exe",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "extensionDistribution": [
        {
          "extension": "exe",
          "count": 1,
          "originalSize": 27
        }
      ],
      "entries": [
        {
          "name": "invoice.pdf.exe",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "sha256": "702cadb38cb8c869a562a0b60825a1bc434f9455b2de04d748350db5dc59c3cc",
      "metadataFilter": {
        "examined": 1,
        "accepted": 0
      }
    },
    {
      "id": "compound-extension",
      "label": "通常の複合拡張子",
      "notDetermined": "圧縮ファイルの中身",
      "fileName": "compound-extension.zip",
      "zipSize": 239,
      "files": 1,
      "folders": 0,
      "totalUncompressed": 114,
      "expansionRatio": 0.4769874476987448,
      "totalFindings": 1,
      "findings": [
        {
          "level": "情報",
          "type": "nested-archive",
          "label": "入れ子の圧縮ファイル",
          "name": "backup.tar.gz",
          "detail": "内部の圧縮ファイルは再帰解析していません。"
        }
      ],
      "findingCounts": {
        "nested-archive": 1
      },
      "suspiciousNames": [
        "backup.tar.gz"
      ],
      "largest": [
        {
          "name": "backup.tar.gz",
          "compressedSize": 115,
          "originalSize": 114,
          "directory": false
        }
      ],
      "extensionDistribution": [
        {
          "extension": "gz",
          "count": 1,
          "originalSize": 114
        }
      ],
      "entries": [
        {
          "name": "backup.tar.gz",
          "compressedSize": 115,
          "originalSize": 114,
          "directory": false
        }
      ],
      "sha256": "d619417553cffab3fe6443d007502127a0e93ffaee98b6e22936566713659dad",
      "metadataFilter": {
        "examined": 1,
        "accepted": 0
      }
    },
    {
      "id": "macro-office",
      "label": "マクロ対応Office形式",
      "notDetermined": "VBAやマクロの存在",
      "fileName": "macro-office.zip",
      "zipSize": 145,
      "files": 1,
      "folders": 0,
      "totalUncompressed": 27,
      "expansionRatio": 0.18620689655172415,
      "totalFindings": 1,
      "findings": [
        {
          "level": "要確認",
          "type": "macro-office",
          "label": "マクロ対応Office形式",
          "name": "book.xlsm",
          "detail": "拡張子 .xlsm のファイルです。VBAの有無は解析していません。"
        }
      ],
      "findingCounts": {
        "macro-office": 1
      },
      "suspiciousNames": [
        "book.xlsm"
      ],
      "largest": [
        {
          "name": "book.xlsm",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "extensionDistribution": [
        {
          "extension": "xlsm",
          "count": 1,
          "originalSize": 27
        }
      ],
      "entries": [
        {
          "name": "book.xlsm",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "sha256": "c6ceb45dffcd8aa28c56383e64c4f465b975efa5812979e999165c0ceb7a9d36",
      "metadataFilter": {
        "examined": 1,
        "accepted": 0
      }
    },
    {
      "id": "nested-archive",
      "label": "入れ子ZIP",
      "notDetermined": "inner.zip内のentryや内容",
      "fileName": "nested-archive.zip",
      "zipSize": 565,
      "files": 2,
      "folders": 2,
      "totalUncompressed": 174,
      "expansionRatio": 0.30796460176991153,
      "totalFindings": 1,
      "findings": [
        {
          "level": "情報",
          "type": "nested-archive",
          "label": "入れ子の圧縮ファイル",
          "name": "archives/inner.zip",
          "detail": "内部の圧縮ファイルは再帰解析していません。"
        }
      ],
      "findingCounts": {
        "nested-archive": 1
      },
      "suspiciousNames": [
        "archives/inner.zip"
      ],
      "largest": [
        {
          "name": "archives/inner.zip",
          "compressedSize": 92,
          "originalSize": 147,
          "directory": false
        },
        {
          "name": "documents/readme.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "extensionDistribution": [
        {
          "extension": "zip",
          "count": 1,
          "originalSize": 147
        },
        {
          "extension": "txt",
          "count": 1,
          "originalSize": 27
        }
      ],
      "entries": [
        {
          "name": "documents/",
          "compressedSize": 2,
          "originalSize": 0,
          "directory": true
        },
        {
          "name": "documents/readme.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        },
        {
          "name": "archives/",
          "compressedSize": 2,
          "originalSize": 0,
          "directory": true
        },
        {
          "name": "archives/inner.zip",
          "compressedSize": 92,
          "originalSize": 147,
          "directory": false
        }
      ],
      "sha256": "6dc7d60d0439cda0667ad46584a090a7ba1a2d654577017023d8e65f9f0bcfbd",
      "metadataFilter": {
        "examined": 4,
        "accepted": 0
      }
    },
    {
      "id": "path-traversal",
      "label": "../を含むパス",
      "notDetermined": "OS上で実際に展開した挙動",
      "fileName": "path-traversal.zip",
      "zipSize": 183,
      "files": 1,
      "folders": 0,
      "totalUncompressed": 27,
      "expansionRatio": 0.14754098360655737,
      "totalFindings": 2,
      "findings": [
        {
          "level": "要確認",
          "type": "traversal",
          "label": "展開先の外側を参照する可能性があるパス",
          "name": "../toolpipo-test-outside.txt",
          "detail": "パスに .. が含まれます。filesystemへの展開は行っていません。"
        },
        {
          "level": "情報",
          "type": "environment-name",
          "label": "環境依存のファイル名",
          "name": "../toolpipo-test-outside.txt",
          "detail": "末尾のdotまたはspaceはOSによって扱いが変わる場合があります。"
        }
      ],
      "findingCounts": {
        "traversal": 1,
        "environment-name": 1
      },
      "suspiciousNames": [
        "../toolpipo-test-outside.txt"
      ],
      "largest": [
        {
          "name": "../toolpipo-test-outside.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "extensionDistribution": [
        {
          "extension": "txt",
          "count": 1,
          "originalSize": 27
        }
      ],
      "entries": [
        {
          "name": "../toolpipo-test-outside.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "sha256": "bc990d0d3c2d19166a2cc59d3bfc8e992a2b59231b64a753c5ea6d44e54d9e01",
      "metadataFilter": {
        "examined": 1,
        "accepted": 0
      }
    },
    {
      "id": "absolute-path",
      "label": "絶対パス形式",
      "notDetermined": "OSや展開ソフトごとの保存先",
      "fileName": "absolute-path.zip",
      "zipSize": 326,
      "files": 2,
      "folders": 0,
      "totalUncompressed": 54,
      "expansionRatio": 0.1656441717791411,
      "totalFindings": 2,
      "findings": [
        {
          "level": "要確認",
          "type": "absolute",
          "label": "絶対パスの可能性",
          "name": "/tmp/toolpipo-test.txt",
          "detail": "root・drive・UNC形式から始まるパスです。"
        },
        {
          "level": "要確認",
          "type": "absolute",
          "label": "絶対パスの可能性",
          "name": "C:\\temp\\toolpipo-test.txt",
          "detail": "root・drive・UNC形式から始まるパスです。"
        }
      ],
      "findingCounts": {
        "absolute": 2
      },
      "suspiciousNames": [
        "/tmp/toolpipo-test.txt",
        "C:\\temp\\toolpipo-test.txt"
      ],
      "largest": [
        {
          "name": "/tmp/toolpipo-test.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        },
        {
          "name": "C:\\temp\\toolpipo-test.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "extensionDistribution": [
        {
          "extension": "txt",
          "count": 2,
          "originalSize": 54
        }
      ],
      "entries": [
        {
          "name": "/tmp/toolpipo-test.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        },
        {
          "name": "C:\\temp\\toolpipo-test.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "sha256": "b8fc4023e360d6967fc996a60331640ecd0069e202f9d78dc0e1ebc482ac4224",
      "metadataFilter": {
        "examined": 2,
        "accepted": 0
      }
    },
    {
      "id": "case-collision",
      "label": "大文字・小文字だけの違い",
      "notDetermined": "上書きや衝突の発生",
      "fileName": "case-collision.zip",
      "zipSize": 272,
      "files": 2,
      "folders": 0,
      "totalUncompressed": 54,
      "expansionRatio": 0.19852941176470587,
      "totalFindings": 1,
      "findings": [
        {
          "level": "情報",
          "type": "case-collision",
          "label": "環境によって名前が衝突する可能性",
          "name": "readme.txt",
          "detail": "Readme.txt と大文字・小文字だけが異なります。"
        }
      ],
      "findingCounts": {
        "case-collision": 1
      },
      "suspiciousNames": [
        "readme.txt"
      ],
      "largest": [
        {
          "name": "readme.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        },
        {
          "name": "Readme.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "extensionDistribution": [
        {
          "extension": "txt",
          "count": 2,
          "originalSize": 54
        }
      ],
      "entries": [
        {
          "name": "Readme.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        },
        {
          "name": "readme.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "sha256": "6f6a908fe3c02229258d26476cec48330838db49b2b7cefc85c4044a14bb7268",
      "metadataFilter": {
        "examined": 2,
        "accepted": 0
      }
    },
    {
      "id": "invisible-character",
      "label": "見えにくいUnicode文字",
      "notDetermined": "内容や文字を入れた意図",
      "fileName": "invisible-character.zip",
      "zipSize": 163,
      "files": 1,
      "folders": 0,
      "totalUncompressed": 27,
      "expansionRatio": 0.1656441717791411,
      "totalFindings": 1,
      "findings": [
        {
          "level": "要確認",
          "type": "control",
          "label": "表示を分かりにくくする制御文字を含む可能性",
          "name": "report​final.txt",
          "detail": "制御文字・Bidi制御・zero-width文字の候補を含みます。"
        }
      ],
      "findingCounts": {
        "control": 1
      },
      "suspiciousNames": [
        "report​final.txt"
      ],
      "largest": [
        {
          "name": "report​final.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "extensionDistribution": [
        {
          "extension": "txt",
          "count": 1,
          "originalSize": 27
        }
      ],
      "entries": [
        {
          "name": "report​final.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "sha256": "4078964e9bafa363a3b20e52b2f822183985617ebaeff5512b5789353fd34747",
      "metadataFilter": {
        "examined": 1,
        "accepted": 0
      }
    },
    {
      "id": "environment-name",
      "label": "末尾のdot・space",
      "notDetermined": "各OS・filesystemでの扱い",
      "fileName": "environment-name.zip",
      "zipSize": 270,
      "files": 2,
      "folders": 0,
      "totalUncompressed": 54,
      "expansionRatio": 0.2,
      "totalFindings": 2,
      "findings": [
        {
          "level": "情報",
          "type": "environment-name",
          "label": "環境依存のファイル名",
          "name": "report.",
          "detail": "末尾のdotまたはspaceはOSによって扱いが変わる場合があります。"
        },
        {
          "level": "情報",
          "type": "environment-name",
          "label": "環境依存のファイル名",
          "name": "folder/name ",
          "detail": "末尾のdotまたはspaceはOSによって扱いが変わる場合があります。"
        }
      ],
      "findingCounts": {
        "environment-name": 2
      },
      "suspiciousNames": [
        "report.",
        "folder/name "
      ],
      "largest": [
        {
          "name": "folder/name ",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        },
        {
          "name": "report.",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "extensionDistribution": [
        {
          "extension": "(拡張子なし)",
          "count": 2,
          "originalSize": 54
        }
      ],
      "entries": [
        {
          "name": "report.",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        },
        {
          "name": "folder/name ",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "sha256": "642c562f8a4fd30a7f6188215dcf0d65bd0de08f97c53295c5c6ffd5d7f9628e",
      "metadataFilter": {
        "examined": 2,
        "accepted": 0
      }
    },
    {
      "id": "deep-path",
      "label": "21フォルダの深いパス",
      "notDetermined": "OSやソフトでのパス長制限",
      "fileName": "deep-path.zip",
      "zipSize": 311,
      "files": 1,
      "folders": 0,
      "totalUncompressed": 27,
      "expansionRatio": 0.08681672025723473,
      "totalFindings": 1,
      "findings": [
        {
          "level": "情報",
          "type": "deep-path",
          "label": "非常に深いフォルダ階層",
          "name": "d01/d02/d03/d04/d05/d06/d07/d08/d09/d10/d11/d12/d13/d14/d15/d16/d17/d18/d19/d20/d21/file.txt",
          "detail": "22階層あります。"
        }
      ],
      "findingCounts": {
        "deep-path": 1
      },
      "suspiciousNames": [
        "d01/d02/d03/d04/d05/d06/d07/d08/d09/d10/d11/d12/d13/d14/d15/d16/d17/d18/d19/d20/d21/file.txt"
      ],
      "largest": [
        {
          "name": "d01/d02/d03/d04/d05/d06/d07/d08/d09/d10/d11/d12/d13/d14/d15/d16/d17/d18/d19/d20/d21/file.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "extensionDistribution": [
        {
          "extension": "txt",
          "count": 1,
          "originalSize": 27
        }
      ],
      "entries": [
        {
          "name": "d01/d02/d03/d04/d05/d06/d07/d08/d09/d10/d11/d12/d13/d14/d15/d16/d17/d18/d19/d20/d21/file.txt",
          "compressedSize": 29,
          "originalSize": 27,
          "directory": false
        }
      ],
      "sha256": "30633d5fd0c34bc01daea172f2399d1492fa3f2faf45cc37812ce3436c2d6215",
      "metadataFilter": {
        "examined": 1,
        "accepted": 0
      }
    },
    {
      "id": "high-compression-ratio",
      "label": "高い圧縮率",
      "notDetermined": "ZIP bombかどうかや安全性",
      "fileName": "high-compression-ratio.zip",
      "zipSize": 12405,
      "files": 1,
      "folders": 0,
      "totalUncompressed": 12582912,
      "expansionRatio": 1014.3419588875454,
      "totalFindings": 1,
      "findings": [
        {
          "level": "要確認",
          "type": "high-ratio",
          "label": "極端に高い圧縮率候補",
          "name": "repeated.txt",
          "detail": "展開後 12 MB、圧縮後 12 KB。ToolPipoの確認用heuristicです。"
        }
      ],
      "findingCounts": {
        "high-ratio": 1
      },
      "suspiciousNames": [
        "repeated.txt"
      ],
      "largest": [
        {
          "name": "repeated.txt",
          "compressedSize": 12283,
          "originalSize": 12582912,
          "directory": false
        }
      ],
      "extensionDistribution": [
        {
          "extension": "txt",
          "count": 1,
          "originalSize": 12582912
        }
      ],
      "entries": [
        {
          "name": "repeated.txt",
          "compressedSize": 12283,
          "originalSize": 12582912,
          "directory": false
        }
      ],
      "sha256": "88121fe48a4f59aae3cd0dd55eaf083cbe500754a3c9ad448557ded4dfa7fbf4",
      "metadataFilter": {
        "examined": 1,
        "accepted": 0
      }
    }
  ],
  "download": {
    "file": "zip-safety-fixtures.zip",
    "bytes": 44602,
    "sha256": "becd33eb67382c0c0a9ee571d1eafff160891a3e4f3f47fb3b31543fca298a9b",
    "url": "https://toolpipo.com/assets/samples/articles/zip-before-extract-safety-test/zip-safety-fixtures.zip"
  },
  "embeddedSnapshotNote": "This embedded results.json is the measurement snapshot. The final outer ZIP byte count and SHA-256 are in the separately published results.json; a ZIP cannot contain its own final checksum."
}