RNA-binding proteins (RBPs) orchestrate essential steps of the viral lifecycle, acting as both proviral and antiviral factors. Yet, the full spectrum of cellular RBPs that bind to viral RNA during infection remains poorly defined. To address this, we developed viral RNA interactome capture (vRIC), a method for systematic identification of proteins bound to viral RNAs in infected cells. Applied to Sindbis virus (SINV), vRIC revealed that SINV RNA engages with hundreds of cellular proteins, including nuclear RBPs that relocate to the cytoplasm upon infection and restrict viral replication. These included components of the U2 small nuclear ribonucleoprotein (snRNP), classically known for splicing pre-mRNAs. U2 snRNP suppresses infection through protein-RNA and RNA-RNA interactions, and its disruption via protein depletion, inhibitors, or antisense oligos targeting U2 snRNA, markedly enhances SINV replication. The accessory complex U2AF1, U2AF2, and SF1, which recognizes intron branch points, is also required for this antiviral effect. Strikingly, U2 snRNP antiviral activity extends to multiple viruses, suggesting function across viral species and families. Viral RNAs are indeed enriched in branch point-like sequences, which may underlie this recognition mechanism, offering new insight into host-virus interactions. Our current work aims to define the "molecular code" that the U2 snRNP requires to bind to viral RNA.