This can happen in a number of ways:
- Intentional damage by hacking is done to your site files
- You install a plugin or theme that has security vulnerabilities
- You have an out of date plugin or theme
- You have an out of date version of WordPress
In these situations, it is not enough to simply update the themes or plugins in question. This is where malware scanning comes in. Malware scanning for WordPress sites is a little bit like a traditional anti-virus service for your computer.
The service checks periodically for patterns which match known vulnerability and security issues and, in the best case, automatically fixes them.
In the case where a breach can’t be automatically fixed, the service also includes priority WordPress support where a professional will help you resolve the issues.