Having a quality that arouses suspicion.
Having signs that suggest a design problem; having a code smell.
Having a bad smell.
a Short Magazine Lee Enfield rifle or one of its derivatives.
Having an attractive appearance intended to generate a favorable response; deceptively attractive.
Employing fallacious but deceptively plausible arguments; deceitful.
Seemingly well-reasoned, plausible or true, but actually fallacious.