Do not accept it. Most likely it's only for Windows. You really don't need it. Instead use the free ClamXav 2.2.5. As for recent concerns see:
Helpful Links Regarding Flashback Trojan
Visit Thomas Reed's site for insight and help: Mac Malware Guide
A Google search can reveal a variety of alternatives on how the remove the trojan should your computer get infected. This can get you started. However, be careful about what you do as new variants of the malware circumvent the efforts of earlier tools.
Also see Apple's article About Flashback malware.
Apple has released Java updates for Snow Leopard and Lion users:
Java for OS X Lion 2012-003; available only for users of Lion with Java installed.
Java for Mac OS X 10.6 Update 8; available only for users of Snow Leopard.
Flashback malware removal tool; available only for users of Lion without Java installed.
Install whichever shows up in Software Update. It removes the malware (if present), updates Java (if present) and tightens up Java settings for the future. You may download from Apple's web site instead of using Software Update, but it's important to know which one to get, because the other two won't work for you.
For the truly paranoid see 10 Simple Tips for Boosting The Security Of Your Mac.
The Norton uninstaller can be found here.
Uninstalling Software: The Basics
Most OS X applications are completely self-contained "packages" that can be uninstalled by simply dragging the application to the Trash. Applications may create preference files that are stored in the /Home/Library/Preferences/ folder. Although they do nothing once you delete the associated application, they do take up some disk space. If you want you can look for them in the above location and delete them, too.
Some applications may install an uninstaller program that can be used to remove the application. In some cases the uninstaller may be part of the application's installer, and is invoked by clicking on a Customize button that will appear during the install process.
Some applications may install components in the /Home/Library/Applications Support/ folder. You can also check there to see if the application has created a folder. You can also delete the folder that's in the Applications Support folder. Again, they don't do anything but take up disk space once the application is trashed.
Some applications may install a startupitem or a Log In item. Startupitems are usually installed in the /Library/StartupItems/ folder and less often in the /Home/Library/StartupItems/ folder. Log In Items are set in the Accounts preferences. Open System Preferences, click on the Accounts icon, then click on the LogIn Items tab. Locate the item in the list for the application you want to remove and click on the "-" button to delete it from the list.
Some software use startup daemons or agents that are a new feature of the OS. Look for them in /Library/LaunchAgents/ and /Library/LaunchDaemons/ or in /Home/Library/LaunchAgents/.
If an application installs any other files the best way to track them down is to do a Finder search using the application name or the developer name as the search term. Unfortunately Spotlight will not look in certain folders by default. You can modify Spotlight's behavior or use a third-party search utility, Easy Find, instead. Download Easy Find at VersionTracker or MacUpdate.
Some applications install a receipt in the /Library/Receipts/ folder. Usually with the same name as the program or the developer. The item generally has a ".pkg" extension. Be sure you also delete this item as some programs use it to determine if it's already installed.
There are many utilities that can uninstall applications. Here is a selection:
For more information visit The XLab FAQs and read the FAQ on removing software.
Why? Because I'm acting stupidly today.... As a matter of fact I first installed Norton (from the Comcast site), THEN started doubting it and came here to ask....
And I actually DID have an uninstall app in the Norton folder........
I'm installing ClamXav, as suggested....
Thanks for all the help today, guys !