Files on USB are Encrypted, but I don't use Safeguard or have a passphrase

Question

Hello, 
 I have a USB with some PDF and TXT files I am trying to open/access data on. However, when I open the files there is just the following text (there is more text, but I don't want to paste information that could give away the data in the files: 
 SafeGuard FileEncryption Copyright 1998-2013 Sophos Group. All rights reserved. SafeGuard is a registered trademark of Sophos........................ 
 p,&lsaquo;&dagger;a&Euml;&ocirc;_&Iacute;1YGvI&euml;&mdash;&ograve;W?&ocirc;se&ndash;&Yuml;............................ 
 
 I noticed I have SGPortable on my USB and when I try to decrypt the files I am prompted for a passphrase with the following message: Enter passphrase for key 'Group_.Authenticated Users@SGN'. 
 Is there any way around this? The only thing I can think of is that I believe my work pc used to use Sophos password protection upon start up a few years ago. Is it possible that Safeguard installed itself on my USB and auto encrypted my files? 
 Any help or insight is appreciated.

MichaelMcLannahan · Accepted Answer

Yes, that&rsquo;s exactly the issue. The company might have had a policy that encrypts external USB to help protect their data. You&rsquo;d have hoped this was common knowledge at the company to prevent &ldquo;accidental&rdquo; encryption of personal USB drives but it would appear sadly not. 
 you are best to contact the company to see if they&rsquo;re still running and using SSG and ask them to assist. There&rsquo;s no backdoor or method to get around this. It&rsquo;s doing exactly as designed and protecting data but your drive has been caught in the process!