Oluwasogo Adekunle Okunade1, Raymond Ternenge Igbudu1 and Emmanuel Gbenga Dada2
1Department of Computer Science, Faculty of Computing, National Open University of Nigeria, Abuja, Nigeria
2Department of Computer Science, Faculty of Physical Sciences, University of Maiduguri, Nigeria
*Corresponding author’s Email: igbuduraymond@gmail.com, doi.org/10.55639/607.05040303
ABSTRACT
Crypto ransomware is a challenging cybersecurity threat that encrypts the files of the victim and demands a ransom in exchange for the decryption key. Traditional signature-based protection methods, such as antivirus and antimalware, have proven in-effective at preventing crypto-ransomware attacks; therefore the production of ransomware is on the rise. Existing methods for early detection of crypto-ransomware attacks during the pre-encryption phase before encryption happens rely on a timing thresholding methodology to set the border of the pre-encryption stage. However, the fixed time threshold strategy, suggests that the samples begin encryption at the exact moment. This is not always the case since timing varies between crypto-ransomware families as a result of the obfuscation techniques used to evade detection. This research work therefore, proposed the creation of a Pre-Encryption Detection-Learning Algorithm (PEDLA). PEDLA monitors the pre-encryption stage for every case separately relying on the initial appearance of any API‟s related to cryptography to establish the pre-encryption stage boundary, whereby features are extracted and used in training a prediction model using the Random Forest machine learning algorithm. The sample data was obtained from widely used ransomware repositories such as VirusShare, Virus total and kaggle.com. The model achieved a detection accuracy of 98.6% with False Positive Rate (FPR) of 1.9%. Four classifiers including Support Vector Machines (SVM), KNearest Neighbour (KNN), Multi Layer Perceptron (MLP), and AdaBoost, were used to evaluate the model’s classification abilities. Furthermore, a comparison was done between the related works and PEDLA. The findings show that PEDLA performed better across most calculated metrics, such as accuracy, precision and recall.
Keywords:
Crypto-ransomware,
Encryption,
Early detection,
Pre-encryption stage,
Signature-based