[Plugin: Wordfence] Have I been hacked?

Hi I’m building a little webshop (not online yet), but yesterday I got this alert message from Wordfence

WordPress core file modified: wp-includes/functions.php

It was changed from:
</body>
2582 </html>
2583 <?php
2584 die();
2585 }
2586
2587 /**

To:
2581 </body>
2582 </html>
2583 <?php
2584 exit(1);
2585 }
2586
2587 /**

I restored it to the original state, will this fix any issue that might have accured?

Also

WordPress core file modified: wp-admin/includes/upgrade.php

From:
2376 function wp_check_mysql_version() {
2377 global $wpdb;
2378 $result = $wpdb->check_database_version();
2379 if ( is_wp_error( $result ) )
2380 die( $result->get_error_message() );
2381 }
2382
2383 /** 2385 /**

To:
2376 function wp_check_mysql_version() {
2377 global $wpdb;
2378 $result = $wpdb->check_database_version();
2379 if ( is_wp_error( $result ) ) {
2380 echo $result->get_error_message();
2381 exit(1);
2382 }
2383 }
2384
2385 /**