Level 12 is just a step more from level 11. The clues don’t really point towards something that would help. So, lets just begin with the normal source code. If you check the source code you will find a meta tag with an attribute name having the value clue and another attribute content having the value as use graphic software.
<meta name="clue" content="use graphic software">
This isn’t much of a clue but yet tells us that this mission is again related to some graphic or image. After looking at the source code the second time I found just one image in the source code as images/logo.gif. Now just open the image, and after enlarging it you will see some text written over Russia. Well, that’s the answer to next level you were looking for.
The next file is puta.php.
Good luck!!!