The effects of noise in the dynamics of Alfvén waves described by the derivative nonlinear Schrödinger equation are investigated. In a complex region of the parameter space, where multistability is observed, an external stochastic source can effectively destroy attractors present in the noise-free system, as well as induce chaotic transients and extrinsic intermittency. In the intermittent regime, the Alfvén wave exhibits random qualitative changes in its behavior as a result of a competition between three attractors and a chaotic saddle embedded in the fractal basin boundary.