A missing texture can't be possible related to the antivirus so, your install is fine.
I think it's a bug that has been there since the Phantom was released, and nobody noticed it. As a workaround, you can copy the following file:
FS9\Aircraft\cloud9_textures\C9F4_CP1.BMP
into any "texture" subfolder of all the "cloud9 Phantom" models. There's no need to copy into each of the "texture.xxxx" livery variation, it's enough make a copy of it in only in the main "texture" folder of every folder that begins with "cloud9 phantom" under FS9\Aircraft