JVM Class Dump

jps -lvm
jhsdb clhsdb --pid 1234
buildreplayjars app

javac -cp javassist.jar -d 123 --release 8 ClassDump.java
jar -uf javassist.jar -C 123 .

-javaagent:javassist.jar

package instrument;

import javassist.ClassPool;

import java.io.ByteArrayInputStream;
import java.lang.instrument.ClassFileTransformer;
import java.lang.instrument.IllegalClassFormatException;
import java.lang.instrument.Instrumentation;
import java.security.ProtectionDomain;

public class ClassDump implements ClassFileTransformer {

    public static void premain(String agentOps, Instrumentation inst) {
        inst.addTransformer(new ClassDump());
    }

    @Override
    public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {
        System.out.println(className);
        try {
            if (className != null && (className.contains("burp") || className.contains("portswigger"))) {
                ClassPool
                        .getDefault()
                        .makeClass(new ByteArrayInputStream(classfileBuffer))
                        .writeFile("D:/Download/burpsuite/");
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }
}