How to scan only certain folders

Something else to add...

You might think you want only to scan those areas, but what happens when a new piece of malware is discovered and detected after you've already downloaded it, scanned it, and moved it to somewhere else on your machine?

If you really don't want to do things this way, I suggest you set up Folder Actions in those locations and script them to "scan now" every time the folder is updated (by adding/removing a file).  You will, however, be severely degrading your protection.

The simplest method of doing something like this is to right click (control click)  on a folder, select "Folder Actions Setup..." from the bottom, select "add - new folder item.scpt" click attach, and then check the "Enable Folder Actions" checkbox.

This will give you a basic alert when the contents of the folder changes.

To make it auto-scan instead, you will need to replace the script with

property dialog_timeout : 30 -- set the amount of time before dialogs auto-answer.

on adding folder items to this_folder after receiving added_items
	try
		tell application "Sophos Anti-Virus"
			scan finder items added_items
		end tell
	end try
end adding folder items to

You can do this easily by copying the above code, clicking the Edit Script button, select all text, paste, save as, and name the new script something like add - scan new items.scpt

Then click the - button on the bottom right of the Folder Actions window to remove the old script, and click the + to add a new one.  Select your new script, and you're done!  From now on, any folder that you set this folder action for will have any new items automatically scanned when they're added.

This method is the same as an on-demand scan, so on-access can (cringe) be disabled if you do this.  As I said, this is not recommended, but it's doable.

Also, you probably want to add your Shared folder to this list as well, as anyone can write to that folder if you're on a network.

Something else to add...

You might think you want only to scan those areas, but what happens when a new piece of malware is discovered and detected after you've already downloaded it, scanned it, and moved it to somewhere else on your machine?

If you really don't want to do things this way, I suggest you set up Folder Actions in those locations and script them to "scan now" every time the folder is updated (by adding/removing a file).  You will, however, be severely degrading your protection.

The simplest method of doing something like this is to right click (control click)  on a folder, select "Folder Actions Setup..." from the bottom, select "add - new folder item.scpt" click attach, and then check the "Enable Folder Actions" checkbox.

This will give you a basic alert when the contents of the folder changes.

To make it auto-scan instead, you will need to replace the script with

property dialog_timeout : 30 -- set the amount of time before dialogs auto-answer.

on adding folder items to this_folder after receiving added_items
	try
		tell application "Sophos Anti-Virus"
			scan finder items added_items
		end tell
	end try
end adding folder items to

You can do this easily by copying the above code, clicking the Edit Script button, select all text, paste, save as, and name the new script something like add - scan new items.scpt

Then click the - button on the bottom right of the Folder Actions window to remove the old script, and click the + to add a new one.  Select your new script, and you're done!  From now on, any folder that you set this folder action for will have any new items automatically scanned when they're added.

This method is the same as an on-demand scan, so on-access can (cringe) be disabled if you do this.  As I said, this is not recommended, but it's doable.

Also, you probably want to add your Shared folder to this list as well, as anyone can write to that folder if you're on a network.