Friday, October 11, 2013



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.


There are two iptable rules available. If your distribution supports Iptables 'u32' module pick this one, otherwise use the 'string' rule.

iptables --insert INPUT -p udp --dport 53 -m u32 --u32 "0x28&0xFFDFDFDF=0x07424142 && 0x2c&0xDFDFDFDF=0x59574f57 && 0x30&0xFFDFDFFF=0x02434f02 && 0x34&0xDFDFFF00=0x554b0000" -j DROP -m comment --comment "DROP DNS Q"

More U32 rules can be found here:

iptables --insert INPUT -p udp --dport 53 -m string --from 40 --to 55 --algo bm --hex-string '|0762616279776f7702636f02756b00|' -j DROP -m comment --comment "DROP DNS Q"
More Iptables rules for the STRING module can be found here:

Source: - Ecatel

Name server:

;; ANSWER SECTION: 10800 IN NS 10800 IN NS 10800 IN NS

;; ADDITIONAL SECTION: 44411 IN A 44411 IN AAAA 2604:3400:a::2 44411 IN A 44411 IN AAAA 2001:4b98:b:a::40 44411 IN A 44411 IN AAAA 2001:4b98:c:521::20


A 243
NS 3
Rsize 4515


Domain name:

Jesy Leu

Registrant type:
UK Individual

Registrant's address:
The registrant is a non-trading individual who has opted to have their
address omitted from the WHOIS service.

Gandi t/a Gandi [Tag = GANDI]

Relevant dates:
Registered on: 07-Oct-2013
Expiry date: 07-Oct-2014
Last updated: 07-Oct-2013

Registration status:
Registered until expiry date.

Name servers:

WHOIS lookup made at 22:35:53 11-Oct-2013

This WHOIS information is provided for free by Nominet UK the central registry
for .uk domain names. This information and the .uk WHOIS are:

Copyright Nominet UK 1996 - 2013.

You may not access the .uk WHOIS or use any data from it except as permitted
by the terms of use available in full at, which
includes restrictions on: (A) use of the data for advertising, or its
repackaging, recompilation, redistribution or reuse (B) obscuring, removing
or hiding any or all of this notice and (C) exceeding query rate or volume
limits. The data is provided on an 'as-is' basis and may lag behind the
register. Access may be withdrawn or restricted at any time.


  1. I had to issue this command to get it to work. Thanks for your help!

    iptables --insert INPUT -p udp -m string --hex-string '|0762616279776f7702636f02756b00|' --algo bm --to 65535 --dport 53 -j DROP

  2. I notice you omitted --start and --stop too, I believe the offsets are incorrect.