Ransomware anti-analysis and evasion techniques: a survey and research directions

Ransomware has been proven to constitute a severe threat to the world's digital assets. Resources or devices' recovery from a Crypto-Ransomware infection is practically infeasible unless an error in the malicious cryptographic implementation has been made, as robust encryption is irreversible. This paper attempts to justify as to why designing and deploying an effective and efficient detective solution against this particular malware category represents a formidable technical challenge. The paper starts with a recent presentation of the Ransomware's epidemic, as reported by the security industry. Subsequently, a taxonomy of Ransomware is presented. The anatomy of the malware's invariant intrusions and infection vectors are illustrated. In addition, the paper navigates and analyzes the various anti-analysis and evasive techniques that are deployable by Ransomware. In every context enumerated in the narrative, the technical difficulty being posed by this malware is illuminated. If a computer security researcher intends to devise a Crypto-Ransomware's preventive solution or a predictive or proactive one, then it is imperative to have a sound perception of the technical challenges that will manifest prior to launching the proposed research project - so as to be equipped to tackle the anticipated problems. This paper concludes with an advance notice underscoring the resilience of Ransomware intrusions and highlighting research open-problems.