Any option to block IPSec intentions

Hello,

for some weeks now we get everyday logs about IPSec connection intentions from the same subnet. Like 2-3 weeks ago we also had them on the other firewall but since one week we only get them at the central firewall.

In the logs we always get scan-39c.shadowserver.org and from the 64.62.197.x. Anything we can do about it?

Thanks!