If you try to fiddle...

If, when an installer is run, it has the appropriate authority--by virtue of the account it is being run under--to make the changes required, then running a perl program under that same authority, will have those same permissions.

On the other hand, if the "anti-virus bit-cop" would detect the perl program as unauthorised, then it would also detect an "installer program" as equally unauthorised.

There is nothing magic about installer programs; they are simply code calling APIs.