Malware

From about one month I receive information from my technical support server that skyfashion files are infected
...../wp-content/themes/skyfashion/mainik.php
I have upgraded wordpress, all plugins, all themes..... and every week the problem is return.
Could you check out the theme skyfashion and upgrade it if necessairly?
Perhaps the problem is with the sky fashion theme so would be great to solve this problem.
Does anyone have a problem with that?