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)
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.