
A malicious downloader often acts as the starting point as it fingerprints the victim's machine and downloads one or more additional malware payloads. Malware infections are increasing in complexity and unfold over a number of stages. Malware affects millions of users worldwide, impacting the daily lives of many people as well as businesses. Finally, in attempting to simulate malware for our experiments, we discovered that the field of malware simulation is relatively unstudied despite its potential and therefore provide recommendations for simulating malware for system-call analysis. Whereas, when trained on system calls gathered at a Kernel, system-wide level, the classifiers' results were less variable. Additionally, the classifiers trained on the user-level data were not as robust against small changes in system calls made. Generally, this threshold was crossed when the simulated ransomware waited 2 s or more between each file it encrypted. The results of our experiments indicated that, in general, the classifiers were more likely to label the simulated samples as malicious once the amount of evasive behaviour present in a sample went beyond a threshold. The simulated samples, like the real samples, are run in a sandboxed environment where data is collected at a user-and Kernel-level. The simulated ransomware gives us the freedom to create samples with different levels of evasive and malicious behaviour. We achieve this by training them on real ransomware and benignware and then testing their ability to detect carefully crafted simulated ransomware. In this paper, we study the extent to which classifiers are dependent on evasive behaviour when identifying malware. There is a risk that classifiers trained using the standard dynamic malware analysis process will only recognise malware by its evasive behaviour rather than a mix of behaviours. This means that if malware does not demonstrate its malicious intent within that time frame and environment, the behaviour observed and subsequently learned may not be the behaviour that needs to be prevented. However, it is usually a restricted form of the preferred environment and malware may only be run for two minutes or less. Dynamic malware analysis has been framed as a potential solution as it runs malware in its preferred environment to ensure that it observes its true behaviour. Malware analysts, therefore, have to find increasingly sophisticated methods to detect malware prompting malware authors to increase the number of evasive techniques employed by their malware. To accomplish this, malware hides its true purpose from its target and malware analysts until it has established a foothold on the victim's machine.

#MACOS MALWARE RUNONLY AVOID DETECTION FOR SOFTWARE#
Malware refers to software that is designed to achieve a malicious purpose usually to benefit its creator.

We demonstrate the utility of this taxonomy by using it to characterize the prevalence of these avoidance methods, to generate a novel fingerprinting method that can assist malware propagation, and to create an effective new technique to protect production systems.

To combat this emerging threat, we have undertaken a robust analysis of current malware and developed a detailed taxonomy of malware defender fingerprinting methods. Recently however, new malware instances have emerged with the capability to check and often thwart these defensive activities - essentially leaving defenders blind to their activities. To combat these threats, defenders of these networks have turned to the collection, analysis, and reverse engineering of malware as mechanisms to understand these programs, generate signatures, and facilitate cleanup of infected hosts.

Many threats that plague todaypsilas networks (e.g., phishing, botnets, denial of service attacks) are enabled by a complex ecosystem of attack programs commonly called malware.
