This paper presents a malware-detection pipeline for Windows API-call sequences that converts variable-length traces into fixed-length behavioral features. API tokens are embedded with Word2Vec and clustered with $K$-means to form a shared behavioral state space, and each trace is summarized by first-order Markov transition frequencies ($S^2$ features). Experiments on 150{,}656 traces with a family-aware split (20\% of families held out for testing) show that linear baselines trained on the full transition representation provide strong and scalable performance. Quantum models are evaluated under explicit computational limits by applying TruncatedSVD to low-dimensional subsets and comparing a fidelity-kernel QSVM and a variational quantum classifier against a matched classical SVC-RBF on identical stratified subsets. Beyond ROC/PR curves, security-oriented operating points are reported by selecting thresholds on validation to enforce high malware recall ($R_{\mathrm{mal}}\ge 0.90$), highlighting the recall trade-off and the scaling cost of quantum kernel evaluation as qubit count increases.
malware detection, API call sequences, Word2Vec, $K$-means, Markov transitions, quantum machine learning, QSVM, VQC
81P68, 68M25, 68T05, 68T10