Cloudsigma has many IPs and those are all from their ranges:
18.104.22.168 - 22.214.171.124 126.96.36.199/22
188.8.131.52 - 184.108.40.206 220.127.116.11/22
18.104.22.168 - 22.214.171.124 126.96.36.199/24
Should you block them? If you do not want that traffic, block it. You need to look at the activity because it may be human visitors or it may be robots. Look at the UAs, look at the requests, that should tell you whether to block or not.