Per Wikipedia, "The Su-34 has 12 pylons for up to 8,000 kilograms (17,635 lb) of ordnance". So I guess most of it is external.
The little rear-protruding pod doesn’t look like it can house them all.
The pod can be anything from an external (refillable in flight) fuel tank to an EW or a FLIR/laser unit, or something else. I'd think it highly unlikely to ever contain ordnance, just on mechanical grounds. But an EW pod is nearly certain, at least according to www.ausairpower.net.
That protrusion is pretty bizarre but probably has a practical purpose. Let’s face it, the Soyuz ain’t very pretty but has proven itself as a useful craft that has outlasted our efforts.
But, again IMHO, 17K doesn’t make it a bomber, just and run of the mill A/F.