After adding 51la statistical code, the website is hijacked and jumps to an illegal website. If you want to retrieve the relevant backdoor webshell file, how can you retrieve it

After adding 51la statistical code, the website will inexplicably jump to the illegal pornographic website on the mobile phone. After removing the relevant 51la js code, the website will return to normal. Now if you want to get the relevant logs, how can you get them