It isn't an antivirus, just a complement, because it doesn't prevent the dangerous software from installing, it just keeps track of the actions that all the software applications carry out, and if it detects something dangerous for the system it notifies it. Norton AntiBot controls the computer at all times, and it detects malware even at the lowest levels within the system. Moreover, the impact it has on the computer's performance is next to nothing.
Another positive effect of Norton AntiBot is that most people won't even realize that it is working. After the installation it will start to work and won't bother you again unless there is really some danger for the system.
Try out Norton AntiBot and use it as a complement for your antivirus.