so now we want to talk about file metadata.
file metadata is a big no- no when it comes to security, anonymity, and privacy.
what people don't realize is when you take a picture or you create a word document, there's a lot of information associated with that file or that folder or whatever it is.
that document specifically on word might show the username, who created it, the type of computer it was created on, the time it was created, the time zone it was created.
an image file might have location.
it might have information on the mobile device if you used a phone, might have the os version, the login, email associated metadata is on a lot of things.
so we want to make sure the files we work with are clean of metadata.
so what we're going to go is what we're going to do is we're going to go into tails, we're going to create a file and i'm going to show you how you can actually use tails to remove file metadata.
so if we hop back over to our tails instance, we can actually go and create a new file here.
what we'll do is we'll use libreoffice.
we'll just use libreoffice writer, which is essentially an open source version of word.
we'll just say our document, right?
we don't need to put a lot of info in here because the metadata isn't in here.
we'll save this.
i made one earlier called this.
so we'll just go ahead and overwrite that.
we'll call it our libreoffice file.
yes, we'll overwrite it.
now we can just simply close this page.
and now what you'll want to do is you want to see what metadata is on there.
so let's actually use the exif tools.
and let me make sure i'm in the right directory here, documents.
and we can use exif tool and we can actually type in this one.
so the exif tool is a built in tool to most linux distributions, and it can actually look at some of the metadata of a file.
so this is all the metadata of a file.
what we can actually do is let's output that to say original metadata.
so now we have a file that actually describes the metadata for us.
so we can keep that open just for comparison in the future.
so we have our original metadata here, right?
this is the same as the output in the command line.
and now what we want to do is in tails itself, there's a really neat metadata eraser tool called metadata cleaner.
if we click into that, we can actually add the file we want to clean the metadata from, which is our libreoffice file.
we can open that and we can clean.
now we're not going to back up.
so we're not going to back up the file, meaning it will overwrite the original file.
so if you want to make sure that doesn't happen, i would create a different name.
but let's, let's just clean here.
click clean.
and there we go.
done.
very quick, very easy to use.
and now if we do that same command, and we'll just say this is the cleaned metadata now as our output, now we have two files to compare.
and we can kind of pull this one out.
now we can compare the two.
so if you look at the cleaned metadata compared to the original metadata, there's a lot less information on the cleaned metadata page.
just looking at the two, right?
this is the whole this is everything in the cleaned.
and now look at the difference, everything in the original.
so what what was removed?
well, things about the date were removed.
creation date is in the original doesn't exist here.
things about the document information, right character count, word count, paragraph count, all gone, where it came from, like what program created it, a preview, all of that is gone.
so what's left in here is really simple information that needs to be in linux or in any operating system to understand the permissions of the file, the general file last change time, and then the actual file name and the file type.
all of those are pretty much required by your operating system to understand and parse the file.
otherwise it's not going to display it correctly.
it might not let you open it.
so these ones are required.
but all the rest of this is not so really awesome that it was able to remove all of that very simple way to clean metadata on files.
and you can actually do this in command line as well.
metadata two is known as the mat two.
man matt.
so matt two is the metadata cleaner.
that's the name of the program.
so matt two, if you look at the man page, you can actually see, you know, information about the tool.
but all you really need to do is you could just say mat two and then the file you want to do, which is our libreoff file and boom, it's done.
and that will automatically create a different file called dot cleaned dot odt, right, it'll add a dot cleaned at the end.
that's how you know it worked.
and that's how it automatically handles the backup situation.
so in the user interface, we had to specifically undo that manually in the command line, it just does it and produces a cleaned version.
so that is how you use the metadata cleaner entails.
very simple, very easy to use.
if you have any questions on that, of course, let me know.
otherwise, we'll see you in the next one.