Trent's company has recently discovered that their DNS information was changed via their registrar. Investigation showed that an administrator's workstation was compromised and that the account details for domain administration were contained on the workstation. What type of DNS-based attack is this?

DNS hijacking can occur in a number of ways, including via the registrar, by changing your organization's DNS servers, or via changes to a local hosts file. DNS-based DoS attacks seek to disable or prevent DNS from working, whereas DNS-based DDoS attacks tend to be amplified and reflected by sending spoofed DNS queries with large results that will bog down the network connection of a targeted system or organization.