If you are seeing queries for this domain, than you are likely participating in DNS Amplification attacks and your DNS server is probably reachable from the internet and has recursion enabled.
If you are seeing responses for this domain.. unlucky. You are currently beeing DDOS-ed! Good luck.
IPtables:
There are two iptable rules available. If your distribution supports Iptables 'u32' module pick this one, otherwise use the 'string' rule.
U32:
iptables --insert INPUT -p udp --dport 53 -m u32 --u32 "0x28&0xFFDFDFDF=0x0541444d && 0x2c&0xDFDFFFDF=0x494e0447 && 0x30&0xDFDFDFFF=0x554c4c02 && 0x34&0xDFDFFF00=0x43410000" -j DROP -m comment --comment "DROP DNS Q admin.gull.ca"
More U32 rules can be found here:
https://github.com/smurfmonitor/dns-iptables-rules/blob/master/domain-blacklist.txt
String:
iptables --insert INPUT -p udp --dport 53 -m string --from 40 --to 55 --algo bm --hex-string '|0561646d696e0467756c6c02636100|' -j DROP -m comment --comment "DROP DNS Q admin.gull.ca"
More Iptables rules for the STRING module can be found here:
https://github.com/smurfmonitor/dns-iptables-rules/blob/master/domain-blacklist-string.txt
Source:
162.211.126.19
Name server:
gull.ca. 86400 IN NS ns4.i-mecca.net.
gull.ca. 86400 IN NS ns5.i-mecca.net.
Response:
TXT 16
Rsize 4024
Whois
Domain name: gull.ca
Domain status: registered
Creation date: 2000/12/30
Expiry date: 2015/12/30
Registrar:
Name: Can Reg (Infinet Communications Group Inc.)
Number: 146
Name servers:
ns4.i-mecca.net
ns5.i-mecca.net
