Hello @oferlaor and thanks for reaching out to us!
An increased attack rate would happen for one primary reason – attackers are more active. Most likely, someone ran a script against your site to see if they could find a security hole. Since all of the requests were blocked, there is nothing you need to do.
You can also disable this email if you want since there is no action you need to take when attacks increase. It’s more of notification for people who may want to dig further. But that would be more out of curiosity than necessity. If you want to disable the option, it’s called “Alert me when there’s a large increase in attacks detected on my site” and you can find it by searching at the top of the Wordfence “All Options” page.
Unfortunately, large attack rates are an everyday occurrence on WordPress sites. That is of course precisely why developed Wordfence!
If you have any other questions or concerns, just let me know!
Thanks again!