This document presents a static malware detection system using data mining techniques. The system extracts raw features from Windows Portable Executable (PE) files including PE header information, DLLs, and API functions. It then selects important features using Information Gain and reduces dimensions using Principal Component Analysis. Three classifiers (SVM, J48, Naive Bayes) are trained on the transformed feature vectors to classify files as malicious or benign. When evaluated on a dataset of over 247,000 files, the system achieved a detection rate of 99.6%.