  We construct examples of deformed Hermitian Yang-Mills connections and
deformed Spin(7)-instantons (also called Spin(7) deformed Donaldson-Thomas
connections) on the cotangent bundle of $\mathbb{C}\mathbb{P}^2$ endowed with
the Calabi hyperK\"ahler structure. Deformed Spin(7)-instantons on cones over
3-Sasakian 7-manifolds are also constructed. We show that these can be used to
distinguish between isometric structures and also between Sp(2) and Spin(7)
holonomy cones. To the best of our knowledge, these are the first non-trivial
examples of deformed Spin(7)-instantons.
