JAR files are Java Archive files, and are really just ZIP containers behind the scenes. If you cannot download the JAR file, try downloading the ZIP file. Any local virus scanner might have an easier time knowing it is just a ZIP file (?)

To change a zip to a jar, just delete the .zip file extension.

Original source: https://pdfbox.apache.org/download.html

Chrome often flags downloads from this site with "Failed - Virus scan failed" - https://support.google.com/chrome/answer/2898334?hl=en-GB#zippy=%2Cvirus-scan-failed-or-virus-detected