http://www.wechall.net/challenge/training/stegano/attachment/index.php
下载图片，用Stegsolve打开，发现有additional bytes，共136。于是
tail -c 136 attachment.jpe > 1.zip
解压后得到密码
但是后来看论坛，直接解压图片都可以。因为
zips store all required information at the end of the file and a typical unzipper basically jumps to the end and follows the pointers from there.