Triffid, Inc., has many remote workers who use their own IT devices to process Triffid's information. The Triffid security team wants to deploy some sort of sensor on user devices in order to recognize and identify potential security issues. Which of the following is probably most appropriate for this specific purpose? $($D$4\mathrm{.}2$ L$4\mathrm{.}2\mathrm{.}2)$