Malicious Code Detection via API Call Time Intervals

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing malicious code detection methods based on dynamic analysis often misidentify normal code as malicious due to similar function names or patterns, and fail to detect variants of malicious code that change function names or patterns, leading to incorrect classifications and undetected threats.

Innovation Solution

A machine learning-based approach that analyzes API function call times by calculating time intervals and determining feature values from these intervals to train a malicious code detection model, which can identify and detect malicious code patterns without significant changes to existing detection models.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If dynamic analysis based on API call information is used for malicious code detection, then detection capability is provided, but normal code with similar function names or patterns is wrongly identified as malicious

Engineering Contradiction:
Improvemalicious code detection accuracyVSAvoidfalse positive rate
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the detection parameters from static API function names to dynamic temporal features including time intervals between API calls, call frequencies, and sequential patterns. This transformation allows the system to distinguish malicious code from normal code even when they use similar function names, by analyzing the temporal characteristics of API invocation patterns.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic analysis of API call timing patterns, where the system continuously monitors and analyzes the temporal dynamics of function calls. By examining when functions are called rather than just what functions are called, the system adapts to detect malicious behavior patterns while avoiding false positives from legitimate applications with similar function sets.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If existing dynamic analysis methods are used, then some malicious code can be detected, but variants that change function names or patterns are not detected

Engineering Contradiction:
Improvedetection coverage against code variantsVSAvoiddetection accuracy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent segments the API call sequence into multiple temporal windows and analyzes each segment independently for specific temporal features. This segmentation approach allows the system to capture different phases of malicious behavior and detect variants by identifying consistent temporal patterns across segments, even when function names or specific patterns change.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent adds temporal dimension to the traditional API call analysis by incorporating time intervals, call frequencies, and sequential timing patterns. This dimensional transformation enables the detection system to identify malicious code variants through their temporal execution characteristics, providing broader detection coverage without sacrificing accuracy.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If machine learning model is trained with API call sequences and temporal features, then detection accuracy improves to 93%, but computational complexity increases

Engineering Contradiction:
Improvemalicious code detection accuracyVSAvoidmodel training and processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts specific critical temporal features from the complete API call sequences, focusing on key parameters such as time intervals between calls, call frequencies, and dominant sequential patterns. This feature extraction approach reduces the dimensionality of the input data for the machine learning model, improving detection accuracy while reducing computational complexity compared to analyzing entire raw call sequences.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentUS11475133B2Method for machine learning of malicious code detecting model and method for detecting malicious code using the same
Publication Date: 2022.10.18 SAMSUNG SDS CO LTD
  • US11475133B2 patent drawing
  • US11475133B2 patent drawing
  • US11475133B2 patent drawing

AI summary

A method of training a malicious code detection model and a method of detecting a malicious code. The method includes acquiring application programming interface (API) call information of called functions from a result log of performing dynamic analysis of a malicious code, calculating time intervals between timestamps using the timestamps which indicate API call times extracted from the API call information, determining a feature value of the malicious code on the basis of the time intervals, and training the malicious code detection model using an API call sequence included in the API call information and the feature value.