How to Build a Malware Detector Using Python?

 How to Build a Malware Detector Using Python?

Introduction

Malware attacks are increasing rapidly, making detection tools essential. In this article, we’ll build a simple Python tool to detect suspicious executable files (PE format) — a foundation for more advanced security projects.

Tools Used

• pefile library: To analyze Windows PE files.

• os module: For file system operations.

The Code

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import pefile
import os

def scan_file(file_path):
    try:
        pe = pefile.PE(file_path)
        print(f"[+] Analyzing: {file_path}")
        
        suspicious_features = []
        
        if pe.is_exe():  # Is it an executable?
            suspicious_features.append("EXE file")
            
        if pe.is_dll():  # Is it a DLL?
            suspicious_features.append("DLL file")
            
        if len(pe.sections) > 5:  # Unusual section count
            suspicious_features.append("Suspicious section count")
            
        if suspicious_features:
            print("⚠️ Warning: File may be malicious!")
            print("Suspicious features:", ", ".join(suspicious_features))
        else:
            print("✅ File appears safe.")
            
    except pefile.PEFormatError:
        print("❌ Not a valid PE file (likely safe).")
    except Exception as e:
        print(f"Error analyzing file: {e}")



# Example usage:
scan_file("sample.exe")

How It Works

1. PE File Analysis:

   • Checks if the file is an EXE or DLL.

2. Suspicious Features Detection:

   • Unusual section counts (malware often adds extra sections).

3. Reporting:

   • Prints a risk assessment report.

Next Steps

• Add a database of known malicious signatures (e.g., suspicious IPs).

• Integrate with open-source antivirus like ClamAV.