studiofive on "[Plugin: Wordfence Security] What does this mean?"

I get this from a Wordfence scan:

File contains suspected malware URL: /mnt/stor6-wc2-dfw1/429320/890212/www.capalabaphysio.com.au/web/content/wp-content/cache/wp-cache-cc58aad9a92c40e03209018548901c23.html

Filename: wp-content/cache/wp-cache-cc58aad9a92c40e03209018548901c23.html
Bad URL: http://www.capalabaphysio.com.au/xmlrpc.php
File type: Not a core, theme or plugin file.
Issue first detected: 55 secs ago.
Severity: Critical
Status New

What does it mean is ocurring when "/mnt/stor6-wc2-dfw1/429320/890212"is placed before the site URL?

I keep getting these messages, I delete the file, run anew scan and get another new lot with the same error theme. Has my site been hacked? Why did Wordfence not stop it?

https://wordpress.org/plugins/wordfence/