By combining a squeezed propagating microwave field and an unsqueezed vacuum field on a hybrid (microwave beam-splitter), we generate entanglement between the two output modes. We verifythat we have generated entangled states by making independent and efficient single-quadrature measurements of the two output modes. We observe the entanglement witness EW=−0.263+0.001−0.036 and the negativity N=0.0824+0.01−0.0004 with measurement efficiencies at least 26±0.1% and 41±0.2% for channel~1 and 2 respectively. These measurements show that the output two-mode state violates the separability criterion and therefore demonstrate entanglement. This shared entanglement between propagating microwaves provides an important resource for building quantum networks with superconducting microwave systems.