This is a simple way to know when a vulnerability in Plesk (or any other software) is being exploited in the wild:
![](https://defragged.org/wp-content/uploads/2020/07/plesk.png)
When the mass scans for it starts. The data is from ISC (isc.sans.org) and shows a massive increase in thenumber of queries for port 8443 (used by Plesk).