Image files with _sophos wrongly listed as User!

Question

I have a problem with about 200 imported image files that have _sophos listed as the Sharing & Permissions name. No idea how they got this but it means unless I change the permissions on all the files Aperture lists them as 'Unsupported Image Format'. If I select add a name to the permissions SophosEndpoint is listed as an option. SophosEndpoint is not listed in System preferences Users and Groups however. Sophos 9.4 Mac OS X 10.11

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bobcook · Accepted Answer

I provided some info in this thread: community.sophos.com/.../10649 
 
Sounds like the system "reused" the account identifier from an old account on your computer, or perhaps an account on another computer. In a UNIX system each user account has a unique identifier, and this numeric ID is often preserved when moving files between computers. When we create our account, the system assigns the next available identifier (we don't choose it nor can we control it). This can make this slightly confusing in situations like yours. 
 
You can, with administrative privileges, change the ownership of any file on your system. Obviously you should do it with care, you can very seriously damage your operating system if you change permissions on the wrong files. But changing ownership on your image files should be safe.

serra · Answer

Hey Peter, 
 Sorry to hear you're having trouble. I haven't heard of this before, so I'm curious if you can send over some screenshots? 
 Also, I'm curious where the files were imported from? Have you tried scanning the files with SAV? 
 As for a fix / workaround, I would suggest using the chown command to give the files the proper permissions. I'm not sure how familiar you are with terminal, but you should be able to do it by following the example below. Please read through the steps and let me know if you have any questions. Note: You will need to be logged into your mac with an admin account to do this. 
 
 How to manually modify permissions on a batch of files in OSX 
 1. Open the 'terminal' app. This normally will put you in your "Home" directory. Use the "pwd" command to confirm. 
 starbuck:~ serra$ pwd /Users/serra 2. Use the 'ls' command to list the files in the current directory starbuck:~ serra$ ls Movies cap3.pcap Applications Music Applications (Parallels) Pictures Desktop Public Documents Downloads stupid Library cap2.pcap 3. Use the "cd" command to change to the directory where the images are located. In my example they are in the "/Pictures/Aperture" directory. (You can always use the "ls" command to see the files in the current directory if you're not sure) starbuck:~ serra$ cd Pictures/ starbuck:Pictures serra$ ls $RECYCLE.BIN Aperture desktop.ini starbuck:Pictures serra$ cd Aperture/ 
 4. Use the "ls -ll" command to view current ownership of the image files. In my example below, we see "oliver" is the current owner, but we are going to change this to "serra" 
 starbuck:Aperture serra$ ls -ll total 0 -rw-r--r-- 1 oliver staff 0 19 Oct 10:18 file1.jpg -rw-r--r-- 1 oliver staff 0 19 Oct 10:18 file2.jpg -rw-r--r-- 1 oliver staff 0 19 Oct 10:19 file3.jpg 5. Use the "chown" command to take ownership of all the image files. Note: ' *.jpg ' means 'apply this change to any file in the directory that has a .jpg extention.' This might not be the case for you, so if your imported files are say, .png files, you would change the command to ' sudo chown youruser *.peg '. When you are prompted for a password, use the password you regularly use to log into your Mac. starbuck:Aperture serra$ sudo chown serra *.jpg Password: starbuck: Aperture serra$ ls -ll total 0 -rw-r--r-- 1 serra staff 0 19 Oct 10:18 file1.jpg -rw-r--r-- 1 serra staff 0 19 Oct 10:18 file2.jpg -rw-r--r-- 1 serra staff 0 19 Oct 10:19 file3.jpg 
 Hopefully that makes sense, but let me know if you have any questions!