Identifying and protecting against surveillance apps installed on client devices

Identifying and protecting against malicious apps installed on client devices. In some embodiments, a method may include (a) identifying client devices, (b) identifying apps installed on the client devices, (c) assigning each of the apps known to be a malicious app with a highest app suspicion score, (d) assigning each of the other apps as an unknown app with a lowest app suspicion score, (e) assigning each of the client devices with a device suspicion score, (f) assigning each of the unknown apps with an updated app suspicion score, (g) repeating (e), and repeating (f) with a normalization, until the device suspicion scores and the app suspicion scores converge within a convergence threshold, (h) identifying one of the unknown apps as a malicious app, and (i) protecting against the malicious app by directing performance of a remedial action to protect the client device from the malicious app.