I had a quick look at you project and couldn't see anything that I thought would cause the warning you got, although as I said previously I don't know a lot about that particular virus warning or what exactly causes it. The only externally referenced files were the images you are hosting at formationgrosman.com.
I do however have a couple of suggests about the story's code itself:
1. The standard (correct) way to remove the Sidebar is to use the UIBar.destroy() function found in the UIBar API section, at least it has been since SugarCube v2.17.0 which I believe was when that function was added.
2. You may want to consider using Line Continuations (and some indentation>?) to make some of you more complex Passages (like Results Revealed) a little easier to read and understand.
eg,
!!What your choices ...
!!!!Dear Ms. Claxton,
''You chose:'' $Claxton
''What it says:'' \
<<if $Claxton is "client">>
\You're right. This ....
\<<elseif $Claxton is "supervisor">>
\You work at a company .....
\<<elseif $Claxton is "new contact">>
\It seems you want to ....
\<<elseif $Claxton is "colleague">>
\She must think you ...
\<<elseif $Claxton is "friend">>
\Your friend probably ...
\<<else>>
\Did you enter the ...
\<</if>>
\
\!!!!Dear Beverly, ...
... obviously I truncated some of the actual content to make the example both shorter and less revealing, but I'm sure you get the general gist of it.