| Algorithm 1 Feature Selection. |
| Input: Training set with permissions and intent static features; |
| Output: Optimal subset of features after selection; 1 |
| 1: Step1: Feature importance ranking |
| 2: The feature importance scores were calculated using chisquare test, analysis of variance Fvalue, and mutual information, respectively.; |
| 3: Removal of features with scores of Nan and 0; |
| 4: Obtain the corresponding candidate feature sets separately; |
| 5: EndStep |
| 6: Step2: Comparing the average performance of different algorithms |
| 7: Apply some detection algorithms to the three candidate feature sets; |
| 8: Calculate the average performance of each algorithm on the three feature sets; |
| 9: EndStep |
| 10: Step3: Obtain the optimal subset of features |
| 11: Compare the average performance and find the best-performing detection algorithm; |
| 12: Compare the performance of this optimal detection algorithm on three feature subsets and find the best performing feature set; |
| 13: EndStep |
| 14: Return the optimal subset of features. |