Hi Guys,
That error obviously means you have a trojan on board :-(.
What you can do is install wordfence and run it on your wordpress website. This one is effective (note: I’m not from wordfence).
Surely it will catch changed files, but in my case it didn’t check the custom theme folder. For example I have ThemeCzetsuya, to modify it I have ThemeCzetsuya-child, the child was not clean. So start searching there, normally the last set of trojan is in either header or footer.php. Look at the bottom of the file and you’ll see encrypted text, delete it.
Hope that fix your problem.
Cheers.
