Is BF3 an electrophile?
Lewis acids are by definition electrophiles. Electrophiles love electrons, or negative charge. Boron has an empty 2p orbital and there exists a strong partial positive charge on the boron due to the extremely electronegative fluorine atoms covalently bound to boron. This strong partial positive character, coupled with a vacant orbital, makes BF3 a potent Lewis acid and thus an electrophile. 

That being said, note that acidity and basicity are both thermodynamic properties, while electrophilicity and nucleophilicity are both kinetic properties. That is, while you can label a Lewis acid an electrophile, it would be incorrect to say, for example, that because a certain Lewis acid is a "strong" Lewis acid, then it must be a strong electrophile. 

Formation Constants; Lewis Acidity