How to use Double Extension Detector
- Select One or more files using the file area.
- Review the selected filenames and sizes.
- Choose any available options and click Check File Names.
- Read the findings, then download the JSON filename report.
FILE TOOL // 028
Double Extension Detector
Spot filenames that use a misleading second extension, such as invoice.pdf.exe. The report also calls out trailing dots, hidden-name patterns, and right-to-left override characters.
Processed locally in your browser
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What this file tool does
Analyzes actual selected filenames for multiple extensions and common disguise patterns without opening or executing the files.
The detector compares the final extension with preceding document or media extensions, executable endings, Unicode direction controls, and trailing-space or dot tricks.
Your selected files stay in this browser session. A double extension can be legitimate, such as archive.tar.gz. The tool distinguishes common compound archive endings but still requires human review.
Supported inputs and limits
A double extension can be legitimate, such as archive.tar.gz. The tool distinguishes common compound archive endings but still requires human review.
| Item | Support |
|---|---|
| Input | One or more files |
| Output | JSON filename report |
| Processing | Local browser session |
Example and practical tips
Practical example
A file called statement.pdf.exe is flagged because the final executable extension controls how the operating system opens it.
Tips
- Keep an untouched copy of important source files.
- Check filenames and sizes before downloading the result.
- Use a current desktop browser for the broadest file API support.
Frequently asked questions
How can I use double extension detector without uploading files?
Choose the requested files in this page and run the tool. Processing happens in your browser, and only the result you download leaves the page.
What does the downloadable json filename report contain?
It contains the actual result or evidence produced from the selected file bytes and metadata, with the important findings shown on screen as well.
Can I use double extension detector on a large file?
Browser memory and device speed set the practical limit. Start with a smaller sample if the file is several gigabytes or the device has limited memory.
Does this tool change my original files?
No. Browser file access is read-only here. The tool creates a separate result for download and does not overwrite the selected originals.
Is a clean result a complete security guarantee?
No. The result covers the checks described on this page. Use specialized desktop or forensic software when you need deeper validation.
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Result details
| Field | Meaning |
|---|---|
| Primary result | Main finding from the selected files |
| Download | JSON filename report |
| Status | Complete only after a real result Blob is created |
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