Can you tell me how the rna virus could cause bleeding?

Need further info: There are many, many viruses that are made out of RNA. In fact there are more RNA viruses than DNA viruses. So the question is 'what virus are you talking about'? There are a number of viral hemorrhagic fevers - perhaps you're referring to one of those? Such as Ebola? I recommend you start here: https://en.wikipedia.org/wiki/Viral_hemorrhagic_fever