Wordpress site hacked - new users being added

I have a Wordpress site, and I keep receiving emails about new users being added - but the emails are all in code. Malware has gotten into the files, and I need to stop it from getting in. For example, I will receive an email which says "New User Account" and the email has the following: <div style="max-width: 560px;padding: 20px;background: #ffffff;border-radius: 5px;margin:40px auto;font-family: Open Sans,Helvetica,Arial;font-size: 15px;color: #666;"> <div style="color: #444444;font-weight: normal;"> <div style="text-align: center;font-weight:600;font-size:26px;padding: 10px 0;border-bottom: solid 3px #eeeeee;">ICF-LI</div> <div style="clear:both"></div> </div> <div style="padding: 0 30px 30px 30px;border-bottom: 3px solid #eeeeee;"> <div style="padding: 30px 0;font-size: 24px;text-align: center;line-height: 40px;">Annette Boettcher has just created an account on ICF-LI.</span></div> <div style="padding: 10px 0 50px 0;text-align: center;">To view their profile click here: [login to view URL]</div> <div style="padding: 0 0 15px 0;"> <div style="background: #eee;color: #444;padding: 12px 15px; border-radius: 3px;font-weight: bold;font-size: 16px;">Here is the submitted registration form:<br /><br /> form_id: 466<br />date submitted: 13 Dec 2018 15:34<br />user_login: annetteboettcher<br />first_name: Annette<br />last_name: Boettcher<br />user_email: AnnetteBoettcher57@[login to view URL]<br /> </div> </div> </div> <div style="color: #999;padding: 20px 30px"> <div style="">Thank you!</div> <div style="">The <a href="[login to view URL]" style="color: #3ba1da;text-decoration: none;">ICF-LI</a> Team</div> </div> </div>