The present invention relates to pyridyl substituted heterocycles according to structural formula (I) or (II), or a pharmaceutically acceptable salt, hydrate, solvate or N-oxide thereof, wherein: the B ring is an aromatic or nonaromatic ring that includes from one to four heteroatoms, wherein X, Y, Z are each, independently of one another selected from C, CH, N, NR16, NR18, S or O, provided that X and Y are not bothe O; U and T are each, independently of one another, selected from C, CH or N; Z is N or CH-; A is N or -CR2-; B is N or -CR3-; D is N or -CR4-; E is N or -CR5 -; G is N or -CR6-; and hydro isomers thereof and pharmaceutical compositions thereof that inhibit replication and/or proliferation of HCV virus. The present invention also relates to the use of the pyridyl heterocycles and hydro isomers thereof and/or pharmaceutical compositions comprising the compounds to treat or prevent HCV infections.