hi all i found this after scaner

“style=\”visibility:hidden” => “CSS styling to hide parts of a web page”,
“ShellBOT” => “This may be a script used by hackers to get control of your server.”,
“uname -a” => “Tells a hacker what operating system your server is running”,
“shell_exec” => “Executes a server command like ls, cd, wget, etc. This may be a script used by hackers.”,
“YW55cmVzdWx0cy5uZXQ=” => “Base64 encoded text found in PHP code that redirects visitors from Google.”,
“” => “HTML code used to hide spammy links, but is also legitimate code.”,
“eval(unescape” => “Could be Javascript code used to hide code inserted by a hacker.”,
“String.fromCharCode” => “Javascript code used to hide suspicious code, but can also be legitimate code.”,
‘$_COOKIE[“yahg”]’ => “YAHG Googlerank.info exploit code. See here for further info.”

how can i fix this hacks??
thanks!!