The effect of static transverse density modulations in the background plasma on fast electron transport is considered. It is shown that such density modulations can drive resistive filamentation in the fast electron beam when the target is sufficiently hot for the Spitzer resistivity to apply. The mechanism of magnetic field generation and filamentation is described both in terms of a semi-analytic model and a linearized analytic model. The results of numerical simulations showing the development of driven filamentation are presented.