..and so he turned his attention to DNS
Posted: Tue May 11, 2010 6:25 pm
So I spent the day playing with DNS and in so doing noticed some interesting things appearing in the logs on one of our DNS servers.
Interesting item 1
Take a look at this:
(actual domain name is redacted, just in case)
The domain in question happens not to have any DNS records on our servers, but that's not the issue. Also of only slight interest is that the IP in question is a nameserver in the Ukraine.
What I'm absolutely fascinated about is the strange random distribution of upper and lower case letters. What on earth is that about? What possible gain could there be from doing this to whoever is doing the lookup (and stinks of badness to me)? Domain names are case-insensitive, are they not?
Interesting item 2
I see loads of these in the logs.
Now the above two domains appear in the CNAMEs in the RRs of one or two domains we host. I know they should not be CNAMES ideally but I don't care -- they are useful as they are.
What I'm facinated about here is why our DNS servers are being queried for their A records. The IPs in the examples above smell of dsl connection (one from brazil).
Broken spambot code maybe?
**
Faris.
Interesting item 1
Take a look at this:
Code: Select all
May 11 23:05:18 dns2 named[16155]: client 88.81.254.216#35370: query (cache) 'GOnredactedWyHOmES.CO.UK/NS/IN' denied
May 11 23:05:18 dns2 named[16155]: client 88.81.254.216#25424: query (cache) 'GOnredactedWyHOmES.CO.uk/MX/IN' denied
May 11 23:05:19 dns2 named[16155]: client 88.81.254.216#53622: query (cache) 'gOnredactedWYhOMeS.Co.uK/NS/IN' denied
May 11 23:05:19 dns2 named[16155]: client 88.81.254.216#12085: query (cache) 'gOnredactedwYhomES.co.UK/MX/IN' denied
May 11 23:05:19 dns2 named[16155]: client 88.81.254.216#22181: query (cache) 'goNredactedwyhoMeS.cO.uK/MX/IN' denied
May 11 23:05:19 dns2 named[16155]: client 88.81.254.216#18947: query (cache) 'GONredactedWYHOmEs.CO.Uk/NS/IN' denied
May 11 23:05:19 dns2 named[16155]: client 88.81.254.216#65308: query (cache) 'GOnredactedwYhOMes.Co.UK/NS/IN' denied
May 11 23:05:19 dns2 named[16155]: client 88.81.254.216#44400: query (cache) 'GonredactedWyHoMEs.CO.Uk/MX/IN' denied
May 11 23:05:19 dns2 named[16155]: client 88.81.254.216#44754: query (cache) 'GONredactedwyHOMEs.Co.uk/NS/IN' denied
May 11 23:05:19 dns2 named[16155]: client 88.81.254.216#22521: query (cache) 'goNredactedwyhoMES.co.UK/MX/IN' denied
May 11 23:05:22 dns2 named[16155]: client 88.81.254.216#51069: query (cache) 'gONredactedwYHOmEs.co.uk/MX/IN' denied
May 11 23:05:22 dns2 named[16155]: client 88.81.254.216#27400: query (cache) 'gONredactedWyHOmes.Co.Uk/MX/IN' denied
May 11 23:05:22 dns2 named[16155]: client 88.81.254.216#64282: query (cache) 'GOnredactedwYhomES.co.Uk/MX/IN' denied
May 11 23:05:22 dns2 named[16155]: client 88.81.254.216#47958: query (cache) 'GoNredactedwyhOmes.co.UK/MX/IN' denied
May 11 23:05:22 dns2 named[16155]: client 88.81.254.216#55543: query (cache) 'gOnredactedwyhOMES.Co.Uk/MX/IN' denied
The domain in question happens not to have any DNS records on our servers, but that's not the issue. Also of only slight interest is that the IP in question is a nameserver in the Ukraine.
What I'm absolutely fascinated about is the strange random distribution of upper and lower case letters. What on earth is that about? What possible gain could there be from doing this to whoever is doing the lookup (and stinks of badness to me)? Domain names are case-insensitive, are they not?
Interesting item 2
Code: Select all
May 11 23:13:18 dns2 named[16155]: client 72.51.107.98#1044: query (cache) 'mx.fakemx.net/A/IN' denied
May 11 23:13:21 dns2 named[16155]: client 187.60.84.211#1039: query (cache) 'tarbaby.junkemailfilter.com/A/IN' denied
Now the above two domains appear in the CNAMEs in the RRs of one or two domains we host. I know they should not be CNAMES ideally but I don't care -- they are useful as they are.
What I'm facinated about here is why our DNS servers are being queried for their A records. The IPs in the examples above smell of dsl connection (one from brazil).
Broken spambot code maybe?
**
Faris.