How to handle mime types, file extension and magic number on file upload, renaming and file download?

I am writing a simple server for file uploading. I want to be able to rename uploaded files (including the file extension) and download files.
For validating the file to upload my plan was to check if the mime type, the file extension and … Continue reading How to handle mime types, file extension and magic number on file upload, renaming and file download?

If my system had been infected prior to submitting important files, could this cause a double and triple file extension and files to show up blank?k [closed]

I was sent an email with attachments from an attorney in a contentious litigation matter despite him embedding the actual attachments at bottom of his email. The links didn’t open until I downloaded Outlook. I submitted exhibits for court … Continue reading If my system had been infected prior to submitting important files, could this cause a double and triple file extension and files to show up blank?k [closed]

Rename file by Ransomware- Does anyone know what is ment by this? [closed]

Does anyone understand what the author means which this (please see the screenshot below).
This is a link to the paper, it’s on page 19 (page 28 if you count all pages):
https://pure.tue.nl/ws/portalfiles/portal/72275825/738228_Mulders_D.A… Continue reading Rename file by Ransomware- Does anyone know what is ment by this? [closed]