This is the icon used by the Humanity theme in Ubuntu to represent a 7zip archive.
Humanity icon theme may be downloaded from Launchpad.
Daniel Foré &lt;Daniel.p.Fore@gmail.com&gt;, Jonian Guveli &lt;jonian.guveli@gmail.com&gt;, and K.Vishnoo Charan Reddy&lt;vish@ubuntu.com
Original uploader was Kjrreid at en.wikipedia