Help me with this php code (need info)

Hello to all team members, does anyone have more info about this php file? Wordfence scan found unknown file in WordPress core: wp-includes/functions2.php. File was created when we registered domain name and start building our website (2,5 years ago)

content of this function2.php below
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<?php
global $adsenseBlock1;
TXT;
function custom_excerpt_length( $length ) {
return 100;
}
add_filter( ‘excerpt_length’, ‘custom_excerpt_length’, 999 );
function new_excerpt_more($more) {
global $post;
return ‘..ID) . ‘”><br />more…‘;
}
function excerpt($num) {
$limit = $num+1;
$excerpt = explode(‘ ‘, get_the_excerpt(), $limit);
array_pop($excerpt);
$excerpt = implode(” “,$excerpt).”..”.'<div class=”source”><p>ID) . ‘”>more…</p></div>’;
echo $excerpt;
}

function image($size) {
$theContent = get_the_content();
$frst_image = preg_match_all( ‘|<img.*?src=[\'”](.*?)[\'”].*?>|i’, $theContent, $matches );

$img = $item[‘image’] = $matches[ 1 ][ 0 ];
$result = ‘‘;
echo $result;

}

function title($num) {
$limit = $num+1;
$title = explode(‘ ‘, get_the_title(), $limit);
array_pop($excerpt);
$title = implode(” “,$title).”…”;
echo $title;
}
add_filter(‘excerpt_more’, ‘new_excerpt_more’);
add_action(‘admin_menu’, ‘lcmp_add_theme_page’);
add_action(‘wp_footer’,’lcmp_theme_options’);

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I really appreciate any help you can provide

Thank you so much

Regards