Plays a role in virus cell tropism, and may be required for efficient virus replication in macrophages. In addition, inhibits IFN-beta-induced IFN-stimulated genes (ISGs) transcription. Mechanistically, degrades host STAT1 and STAT2 through apoptosis and ubiquitin-proteasome pathways respectively. Interacts with host STAT1; this interaction mediates STAT1 degradation through apoptosis. Interacts with host STAT2; this interaction mediates STAT2 degradation through the proteasome. Expressed in the early phase of the viral replicative cycle. Belongs to the asfivirus MGF 360 family.