CompTIA Exam CAS-003 Topic 4 Question 4 Discussion

An organization's mobile device inventory recently provided notification that a zero-day vulnerability was identified in the code used to control the baseband of the devices. The device manufacturer is expediting a patch, but the rollout will take several months

Additionally several mobile users recently returned from an overseas trip and report their phones now contain unknown applications, slowing device performance Users have been unable to uninstall these applications, which persist after wiping the devices Which of the following MOST likely occurred and provides mitigation until the patches are released?