Zero-Ran Sniff: A zero-day ransomware early detection method based on zero-shot learning

Ransomware attacks, which blackmail victims into paying a ransom by locking their devices or encrypting their files, have become one of the major threats to network security. Conventional anti-ransomware tools often fail to detect zero-day ransomware attacks due to the inability to obtain zero-day ransomware signatures in advance to train detection models. In addition, zero-day ransomware attacks often use sophisticated encryption techniques to launch attacks on new vulnerabilities, and these encryption attacks cause irreversible damage to victims' digital files even if they choose to pay a ransom. It is therefore urgent and important to identify unknown ransomware attacks as early as possible, i.e. before the stage of encryption. To this end, this paper proposes Zero-Ran Sniff (ZRS), an early zero-day ransomware detection method based on zero-shot learning, which can detect zero-day ransomware attacks in the early stage. ZRS leverages the portable executable header (PE header) feature from executable files to identify ransomware. It comprises two stages: an auto-encoding network-based core attribute learning (AE-CAL) stage and a self-attentive mechanism-based convolutional neural network inference Stage (SA-CNN-IS). During the AE-CAL stage, the core features of known and unknown classes of ransomware are extracted using self-encoding networks, and the SA-CNN-IS phase identifies ransomware. To the best of our knowledge, we are the first to explore the use of zero-shot learning for zero-day ransomware early detection. Experimental results demonstrate that the proposed ZRS outperforms traditional machine learning methods. Compared to previous zero-day detection work, ZRS achieves a recall of 98.47% and an accuracy of 96.31%