Friday, January 17, 2014

Domain: kvfn.ru

Domain: kvfn.ru

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=0x044b5646 && 0x2c&0xDFFFDFDF=0x4e025255 && 0x30&0xFF000000=0x00000000" -j DROP -m comment --comment "DROP DNS Q kvfn.ru"

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 49 --algo bm --hex-string '|046b76666e02727500|' -j DROP -m comment --comment "DROP DNS Q kvfn.ru"
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:


93.174.95.57

Name server:


;; ANSWER SECTION:
kvfn.ru. 20379 IN NS ns1.reg.ru.
kvfn.ru. 20379 IN NS ns2.reg.ru.


Response:


A 242
NS 2
SOA 1
Rsize 3968


Whois


% By submitting a query to RIPN's Whois Service
% you agree to abide by the following terms of use:
% http://www.ripn.net/about/servpol.html#3.2 (in Russian)
% http://www.ripn.net/about/en/servpol.html#3.2 (in English).

domain: KVFN.RU
nserver: ns1.reg.ru.
nserver: ns2.reg.ru.
state: REGISTERED, DELEGATED, UNVERIFIED
person: Private Person
registrar: REGRU-REG-RIPN
admin-contact: http://www.reg.ru/whois/admin_contact
created: 2013.11.09
paid-till: 2014.11.09
free-date: 2014.12.10
source: TCI

Last updated on 2014.01.18 03:21:37 MSK




3 comments:

  1. Thank you for this post.

    One of our clients have met the same attack. It has been continuing for last 4 days, but spoofed IP address is different, it is 89.38.143.200.
    Closing input on our end didn't help much, because incoming request rate (even small packets 73 bytes each) takes 1/2 of our input bandwidth.

    ReplyDelete
  2. Proved himself under such an attack here made ​​logs DNS server
    http://yadi.sk/d/CXLjSBYGH8xSs

    ReplyDelete
  3. Proved himself under such an attack here made ​​logs DNS server
    http://yadi.sk/d/CXLjSBYGH8xSs

    ReplyDelete