Substituted benzonitriles are disclosed having the formula ##STR1## wherein X represents O or S; R.sub.1 represents bromo, chloro, fluoro, phenoxy, loweralkylthio, loweralkylsulfinyl, loweralkylsulfonyl, loweralkylaminosulfonyl, diloweralkylaminosulfonyl or benzoyl; and R.sub.2 represents hydrogen, bromo, chloro or fluoro with the proviso that R.sub.2 is hydrogen when R.sub.1 is a substituent other than bromo, chloro or fluoro. The compounds of the invention exhibit antiviral activity. Methods of use based on the antiviral activity of the compounds are also disclosed, as well as compositions which comprise a carrier in combination with a suitable antiviral active compound.