The Alot Toolbar is malware, pure and simple, but according to Alot's website they do not support the Apple OS, so how you managed to install it is a bit of a mystery:
http://www.spywareremove.com/removeALOTToolbar.html
where among other things it says:
Deleting ALOT Toolbar can be done easily by any anti-malware program with a reasonably updated threat database. Just remember to close all browser windows when your favorite anti-malware application is scanning your system, or else ALOT Toolbar may make it through unscathed!
Try with ClamXav and/or MacScan. Full information here:
User Tip on Viruses, Trojan Detection and Removal, as well as general Internet Security and Privacy:
https://discussions.apple.com/docs/DOC-2435
The User Tip (which you are welcome to print out and retain for future reference) seeks to offer guidance on the main security threats and how to avoid them, including how to prevent, detect and/or remove the Flashback Trojan.