Viral protein involved in the evasion of host innate defense by inhibiting the interferon regulatory factor-7 (IRF7) protein. Viral infection triggers the phosphorylation and activation of IRF7. The activated IRF7 migrates to the nucleus leading to the transcriptional activation of the IFN-alpha and IFN-beta genes. Some viral proteins prevent IRF7 phosphorylation and nuclear activation. Ebola virus VP35 interacts with IRF7 and hijacks the cellular SUMOylation machinery for its advantage to increase IRF7 SUMOylation thereby disabling its activity.