Unequivocal palaeontological evidence for viruses is usually absent. A specimen of the extinct predatory cockroach Stavba babkaeva gen. et sp. n. from Cretaceous Myanmar amber (98 Ma) shows symptoms of Deformed Wing Virus infection caused by pathogenic DWV-Iflavirus. The hindwing is undeveloped and both curled forewings are symmetrically deformed, differing from environmentally caused asymmetries known from Pripyat and Fukushima. While some unknown cockroach mutation might have the same symptoms, ontogenetic defects (such as incomplete moulting) differ in complete lack of sclerotization, modified forewing bases and presence onboth wings. Post-depositional, taphonomic influence can be excluded due to local character of the deformation (forewings on both sides) while other areas are undeformed. Drying shrinking can be excluded due to brittle character of the wing, which would crack instead - and it could not, be local either. Pathogenic RNA-viruses probably circulated among vertebrates and invertebrate decomposers/predators in the dinosaur-age ecosystems. Our discovery complements an indirect putative evidence of Retrovirus infection that modified dinosaur bones.