phpstudy found multiple backdoor Trojans. Has anyone encountered them?

Question

Scanning found that there are 3 web backdoors on the server, among which the web backdoor files are as follows:
1. PHP one-sentence Trojan, path: c:/phpstudy/phptutorial/www/phpMyAdmin/libraries/Config.class.php
2. PHP one-sentence Trojan, path: c:/phpstudy/phptutorial/www/phpMyAdmin/libraries/schema/User_Schema.class.php
3. PHP execution Trojan, path: c:/phpstudy/phptutorial/www /phpMyAdmin/libraries/sysinfo.lib.php

Answer 1

Or download a new file again and compare the differences.

Answer 2

Open the file and take a look