  Increasing reliance on Information and Communication Technology~(ICT) exposes
the power grid to cyber-attacks. In particular, Coordinated Cyber-Attacks
(CCAs) are considered highly threatening and difficult to defend against,
because they (i) possess higher disruptiveness by integrating greater resources
from multiple attack entities, and (ii) present heterogeneous traits in
cyber-space and the physical grid by hitting multiple targets to achieve the
attack goal. Thus, and as opposed to independent attacks, whose severity is
limited by the power grid's redundancy, CCAs could inflict disastrous
consequences, such as blackouts. In this paper, we propose a method to develop
Correlation Indices to defend against CCAs on static control applications.
These proposed indices relate the targets of CCAs with attack goals on the
power grid. Compared to related works, the proposed indices present the
benefits of deployment simplicity and are capable of detecting more
sophisticated attacks, such as measurement attacks. We demonstrate our method
using measurement attacks against Security Constrained Economic Dispatch.
