The post-transcriptional removal by a virus of the 5' triphosphate group of their viral RNA, thereby preventing host RIG-I from recognizing viral RNA in the host cell. The intracellular pattern recognition receptor RIG-I (also known as DDX58) recognizes viral RNAs containing 5' triphosphates; removal by the virus of the 5'-terminal triphosphate group from their genome protects the viral RNA from RIG-recognition.