I'm not at all sure that Shodan is blocked on
amprgw. There are
more than 2,000 IP addresses that are blocked, with more being added
from time to time, plus there are a number of tcp and udp destination
ports that are blocked from all IP addresses, but there's no way
to be sure that these lists include all Shodan and other scanners.
I have blocked some known Shodan addresses and subnets, and indeed even
a hoster that is known to be a cesspool and accomodates Shodan and the likes:
66.240.192.138 # census8.shodan.io
66.240.205.34 # malware-hunter.census.shodan.io
66.240.219.146 # burger.census.shodan.io
66.240.236.119 # census6.shodan.io
71.6.128.0/17 # cesspool! (including shodan.io, project sonar)
80.82.64.0/20 # ECATEL/QUASI (including shodan.io 80.82.77.139)
82.221.105.6 # census10.shodan.io
82.221.105.7 # census11.shodan.io
89.248.160.0/20 # ECATEL/QUASI (incl shodan.io 89.248.167.131 89.248.172.16)
93.174.88.0/21 # ECATEL/QUASI (incl shodan.io 93.174.95.106)
94.102.48.0/20 # ECATEL/QUASI (incl shodan.io 94.102.49.190 94.102.49.193)
107.6.151.192 # security.census.shodan.io
107.6.151.193 # security.census.shodan.io
107.6.151.194 # security.census.shodan.io
107.6.151.195 # security.census.shodan.io
185.163.109.66 # goldfish.census.shodan.io
185.181.102.18 # turtle.census.shodan.io
198.20.69.72/29 # shodan.io
198.20.69.96/29 # shodan.io
198.20.70.112/29 # shodan.io
198.20.87.96/29 # shodan.io
198.20.99.128/29 # shodan.io
(of course many others, these are just the shodan.io entries)
I also have some iptables rules that capture TCP SYN to addresses that are not registered
in DNS and
forwards them to an nflog socket to be picked up by some scripts that finds those that are
repeat
offenders. Those are logged as candidates for blocking. But I don't bother to block
everything,
I run reverse-DNS on them to see if it has some signature patterns like
"research", "scan" etc or
one of the known names like shodan.io
stretchoid.com etc.
And irregularly I just sort the entire list and glance over it to see if there are
clusters of
addresses and do a whois to see if they belong to some common network. Names like
DigitalOcean
pop up quite regularly but of course they are just cloud hosters that could also host
bonafide
services.
Rob