Problem hacking attempt on dle 12?

Put script parsing in custom field a link to the trailer from YouTube! It worked!! But when adding an article (he spars all the rules), on the website the article instead of the roller at the top of the unit: hacking attempt, and at the bottom:" width="560" height="315" frameborder="10"> see screen.
I understand that somewhere nakosyachil with DLE 12, but where to dig? In old news, it works! Changed the template, no changes! The author of the parsing't seen before!