Symptoms
- Browser shows a warning that the file may be harmful
- Antivirus quarantines the file immediately after download
- Download is blocked or automatically deleted
- File came from a source you're not fully certain about
Likely causes
- CommonFile genuinely contains malwareSecurity software correctly detects many malicious files before they can run.
- PossibleFalse positive on a legitimate fileLess common or newly released software can occasionally be misidentified by antivirus heuristics.
- PossibleDownloaded from an untrusted or modified sourceA file from a third-party mirror or unofficial site can be bundled with unwanted extras even if the original file was safe.
What to do
- Check that you're downloading from the software's official website, not a third-party mirror or search ad.
- Read the specific warning message, since it sometimes names the type of threat detected.
- If you trust the source completely, check the file's official checksum (if provided) against the downloaded file to confirm it wasn't tampered with.
- Search online for others reporting the same file as a false positive with that specific antivirus.
- When in doubt, don't override the block; find an alternative trusted source or contact the software developer.
- If you do decide to proceed, scan the file with a second independent scanner before opening it.
- Keep the block in place and delete the file if there's any real uncertainty about its safety.
When to call a pro
If you need a specific software tool for work and it keeps getting flagged, check with your IT department or the software vendor directly before proceeding.
Safety
Use caution
Do not override a security warning and open a flagged file unless you can verify the exact source and integrity of the download.