Most of us know how the Domain Name System (DNS) is a critical piece of our network infrastructure and have at least one tool to keep DNS requests current and clear of potential abuses. Sometimes a little common sense and knowledge of your system log files and the DNS requests contained therein can go a long way toward understanding when your enterprise network infrastructure has been breached. I note a tale from the Cisco Talos blog how they just used some common sense research in my latest blog post for SecurityIntelligence.com today.