Abstract-With the increasing popularity of Android operating system, its security concerns have also been raised to a new horizon in past few years. Different researchers have introduced different approaches in order to mitigate the malware attacks on Android devices and they succeed to provide security up to some extent but these antimalware techniques are still resource inefficient and takes longer time to detect the malicious behavior of applications. In this paper, basic security mechanisms, provided by Google Android, and their limitations are discussed. Also, the existing antimalware techniques which lie under the basic detection approaches are discussed and their limitations are also highlighted. This research proposes a light weight instant malware detector, named as InstDroid, for Android devices that can identify the malicious applications immediately. Through experiments, it is shown that InstDroid is an instant malware detector that provides instant security at low resource consumption, power and memory, in comparison to other well-known commercial antimalware applications.