Hacker 10 – Security Hacker

Tag: remove file metadata

  • Erase hidden data with the Metadata Anonymisation Toolkit

    Erase hidden data with the Metadata Anonymisation Toolkit

    Metadata embedded in a document or media file can tell a lot about its author, creation time and date, original file author and modifications, location on a computer network where data was created, standards used and custom metadata can all be included in text documents, images, PDFs, spreadsheets, video files, music and others, most people are not even aware that they are leaking information in the documents they publish on the Internet and free tools like Metagoofil, included with Backtrack, can easily extract this metadata and expose who is behind certain document or image and where and when it was taken.

    Supported file formats

    – Portable Network Graphics (PNG)
    – JPEG (.jpeg, .jpg, …)
    – Open Document (.odt, .odx, .ods, …)
    – Office Openxml (.docx, .pptx, .xlsx, …)
    – Portable Document Fileformat (.pdf)
    – Tape ARchive (.tar, .tar.bz2, .tar.gz)
    – ZIP (.zip)
    – MPEG Audio (.mp3, .mp2, .mp1, .mpa)
    – Ogg Vorbis (.ogg)
    – Free Lossless Audio Codec (.flac)
    – Torrent (.torrent)

    Tails Metadata Anonymisation Toolkit
    Tails Metadata Anonymisation Toolkit

    The Metadata Anonymisation Toolkit will remove all metadata in files leaving it empty, however watermarks or steganographic tags won’t be removed but unlike metadata being added by default by many utilities, like Microsoft Office adding author name and smartphones adding GPS coordinates in photographs, watermarks are not usually inadvertently added and the original author will likely be aware of their existence, often inserted to track down forbidden sharing of confidential documents or pre-release movie versions. Summing up, MAT will protect you from accidental metadata leakage but not from customized metadata specifically included to track down the author.

    This software can be found in Tails, JonDo Live-CD and Debian Linux, if you need a Windows or MAC tool check my list of programs to edit Exif data.

    Visit Metadata Anonymisation Toolkit homepage

  • Remove files metadata with BatchPurifier

    Remove files metadata with BatchPurifier

    Every time you create a document, take a digital photograph or edit a movie, hidden data called metadata will be embedded inside the file, that data can contain the author’s name,  date, software or camera used, copyright notices and even GPS Geolocation showing the exact location where a photograph was taken. BatchPurifier is a tool to remove metadata from dozens of different files, the Lite version reviewed here only works with .jpeg images.

    Metadata found on JPEG files  

     Camera manufacturers and image editing software companies can come up with their own proprietary metadata embedding system embodying anything the developer wants to your photographs, typically a digital JPEG image metadata will contain:

    • EXIF (Exchangeable Image File Format) data automatically added to photos by all digital cameras and some scanners, details stored in EXIF show the date and time a photo was taken, camera brand and model, hardware unique serial number, exact location if the camera had GPS enabled (i.e. iPhone), and a small thumbnail of the photo that sometimes is not updated by software after you edit the image leading to a possible recovery of the original file.
    • XMP (Extensible Metadata Platform) is added by software tools and it contains details given by the user, like keywords, notes, description and category.
    • ICC profile contains colour management data used to be able to view a photograph in another device with different specs.
    BatchPurifier image metadata removal
    BatchPurifier image metadata removal

    BatchPurifier Lite has a five step wizard interface guiding you through the metadata removing process giving substantial information on a side bar about what each acronym means, you can choose to only remove part of the hidden data ticking a checkbox next to each attribute, at the end you will be given the choice to save the image as new or overwrite the original file. It is possible to remove thousands of images metadata at once adding multiple jpegs or a whole folder including subfolders and even compressed .zip files with images inside.

    Optionally there is no need to open up the program to clear an image metadata, BatchPurifier integrates with Windows shell menu, advanced users can use BatchPurifier from command line integrating it with a script, this could be used for example to automatically get rid of all metadata in files stored inside a certain folder .

    Visit BatchPurifier homepage