Domain: svist21.cz

Domain: svist21.cz

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=0x07535649 && 0x2c&0xDFDFFFFF=0x53543231 && 0x30&0xFFDFDFFF=0x02435a00 && 0x34&0xFFFF0000=0x00FF0000" -j DROP -m comment --comment "DROP DNS Q svist21.cz"

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 54 --algo bm --hex-string '|077376697374323102637a0000ff|' -j DROP -m comment --comment "DROP DNS Q svist21.cz"
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:

No IP source for this domain

Name server:

;; ANSWER SECTION:
svist21.cz. 1770 IN NS ns5.gransy.com.
svist21.cz. 1770 IN NS ns.gransy.com.
svist21.cz. 1770 IN NS ns2.gransy.com.
svist21.cz. 1770 IN NS ns4.gransy.com.
svist21.cz. 1770 IN NS ns3.gransy.com.

Response:

A 15
DNSKEY 5
MX 8
NS 13
NSEC 2
RRSIG 10
SOA 3
SPF 3
TXT 4
Rsize 6800