Tag Archives: DNS Tools

How reliable is DNS?

DNS is the backbone of the Internet.  It contains all the information to properly route a customer to your site and begin the transaction, when properly configured.  For example:

  • The A record translates your domain, like mxtoolbox.com, to an IP address of the server.
  • The MX record tells your customers’ email servers what IP address to use when sending email.
  • CNAME records associate one domain name with another domain, which can be used to associate one brand with another.
  • SOA specifies what DNS servers are authoritative for a domain

There are many different record types for different purposes, but the beauty of DNS is that it just works.

Until recently…

In May, hackers added a domain to the St Louis Federal Reserve’s research website and setup a clone of the website that was virtually identical to the existing page.  Using this new page, they grabbed a number of logins from unwitting researchers.

In March, hackers targeted 10000+ GoDaddy customers by adding hidden subdomains.  While at the time of the article only a third of the subdomains had been used, it indicates a new type of attack that leverages Small Businesses and their brands for nefarious purposes.

So, what is this attack?

Think of DNS as a phone book for your online presence.  It contains everything a customer needs to find you: your name, address and telephone number.  What if a criminal could call up the Yellow Pages and change your address without you knowing?  Or, change a digit on your phone number?  You might not even notice at first, but new and existing customers might go to the new location or call the new phone number.

What if the criminal made a store front that looked like yours but instead of providing your quality product, the sold cheap knock offs for the same price?  Your brand would suffer and you might go out of business.

Unfortunately, this costs a lot of money and is pretty easy to spot.  However, with DNS, criminals can hack 10000 domains at a single registrar and go undetected.  This type of attack is becoming more common and everyone from a small business to a large enterprise needs to be aware of the possibility that their DNS is at risk.

Monitor your DNS for Changes

MxToolbox recently launched DNS Zone Protect, a monitoring solution for all your DNS, that gives you immediate warning when any change is made to your DNS.  With DNS Zone Protect, you get instant notification of changes to your domain’s DNS.  This new monitor uses AXFR to monitor your domain’s DNS and compares it to previous DNS configurations.  When a change is made, we flag it and notify you.  You get peace of mind knowing that changes to your DNS are being externally monitored by MxToolbox.




DNS Batch Tool

Have you ever needed to lookup DNS on a large list of IPs?  How about parsing a security log to see where a potential threat is coming from?  Combing through the log and getting the full list of IPs can be tedious and tiresome.  And, then you still have to run the DNS checks one-by-one or write a script to do it for you.

Or, you could come to MxToolbox where we have all the cool tools…

That’s right, we’ve launched a DNS Batch Lookup Tool that does all that for you.  Available to all MxToolbox Professional users, DNS Batch Tool eliminates the time-consuming work of parsing text for IP addresses and repetitive DNS lookups.

You can find it on the main menu of the MxToolbox Professional interface* along with our premium monitors like DNS Zone Protect and MailFlow Monitoring.


DNS Batch Tool provides takes simple text as the main input.


As, you can see below, I’ve copied an entire email into the tool so I can see lookup routing information for my most recent campaign.  I could also use security logs or a pre-generated list of IP addresses.


DNS Batch Tool parses the text file and automatically extracts all the IP addresses.



Processing these IP addresses yields reverse host name, country, region and city information, AS number and AS name.



Note: you must be a paid user to access MxToolbox Professional.