Implemented a nitro spam checking function

UPBot Code/Actions/CheckSpam.cs

@@ -0,0 +1,165 @@
+using DSharpPlus.CommandsNext;
+using DSharpPlus.Entities;
+using System.Threading.Tasks;
+using System;
+using System.Text.RegularExpressions;
+using DSharpPlus;
+using DSharpPlus.EventArgs;
+/// <summary>
+/// Command used to check for false nitro links and spam links
+/// author: CPU
+/// </summary>
+public class CheckSpam : BaseCommandModule {
+  readonly static Regex linkRE = new Regex(@"http[s]?://([^/]+)/");
+  readonly static Regex wwwRE = new Regex(@"^w[^\.]{0,3}.\.");
+
+  string[] testLinks = { "discord.com", "discordapp.com", "discord.gg",
+
+    "discrodapp.com", "discord.org", "discrodgift.com", "discordapp.gift", "humblebundle.com", "microsoft.com", "google.com",
+    "discorx.gift", "dljscord.com", "disboard.org", "dischrdapp.com","discord-cpp.com", "discord-nitro.ru.com","discörd.com","disçordapp.com","dlscord.space",
+    "discod.art", "discord-nitro.site", "disscord-nitro.com", "dirscod.com", "dlscord.in", "discorcl.link", "discorb.co", "discord-nitro.su", "dlscord.org", "discord-give.org",
+
+    "steamcommunity.com","store.steampowered.com",
+    "steancomunnity.ru", "streamcommunnlty.ru", "streancommunuty.ru", "streamconmunitlu.me", "streamconmunitlu.me", "stearncomminuty.ru", "steamcommunytu.ru",
+    "steamcommnuitry.com", "stearncomunitu.ru", "stearncormunsity.com", "steamcommunytiu.ru", "streammcomunnity.ru", "steamcommunytiy.ru", "stearncommunytiy.ru", "strearncomuniity.ru.com",
+    "steamcomminytiu.ru", "steamcconuunity.co", "steamcomminytiu.com", "store-stempowered.com", "stemcomnunity.ru.com", "steamcommynitu.ru", 
+    "steamcommurnuity.com", "steamcomminutiu.ru", "steamcommunrlity.com", "steamcommytiny.com", "steamcommunityu.ru", "steamgivenitro.com","steamcommunity.link",
+
+    "epicgames.com","www.epicgames.com","ww2.epicgames.com","epycgames.com",
+    /*
+    "mvncentral.net", "vladvilcu2006.tech", "verble.software", "jonathanhardwick.me", "etc.catering", "tlrepo.cc", "khonsarifamily.tech", "batonrogue.tech", "verbleisover.party", 
+    "grabify.link", "bmwforum.co", "leancoding.co", "spottyfly.com", "stopify.co", "yoütu.be","minecräft.com", "freegiftcards.co", "särahah.eu", 
+    "särahah.pl", "xda-developers.us", "quickmessage.us", "fortnight.space", "fortnitechat.site", "youshouldclick.us", "joinmy.site", "crabrave.pw", "lovebird.guru", "trulove.guru", 
+    "dateing.club", "otherhalf.life", "shrekis.life", "datasig.io", "datauth.io", "headshot.monster", "gaming-at-my.best", "progaming.monster", "yourmy.monster", "screenshare.host", 
+    "imageshare.best", "screenshot.best", "gamingfun.me", "catsnthing.com", "mypic.icu", "catsnthings.fun", "curiouscat.club", "gyazo.nl", "gaymers.ax", "ps3cfw.com", "iplogger.org",
+    "operation-riptide.click", "xpro.gift","lemonchase.club","xn--yutube-iqc.com", "yȯutube.com","tournament-predator.xyz",
+    */
+    };
+
+  public void Test() {
+    for (int i = 0; i < testLinks.Length; i++) {
+      float dist = CalculateDistance(testLinks[i], out string probableSite);
+      bool risk = false;
+      int leven = 1;
+      float riskval = 0;
+      if (dist != 0) {
+        leven = GetDamerauLevenshteinDistance(testLinks[i], probableSite);
+        riskval = dist / (float)Math.Sqrt(leven);
+        risk = riskval > 3;
+      }
+      string rvs = riskval.ToString("f2");
+      while (rvs.Length < 6) rvs = "0" + rvs;
+      Console.WriteLine(rvs + " / " + dist.ToString("000") + " / " + leven.ToString("00") +
+        (risk ? "   RISK! " + probableSite : "") + " <= " + testLinks[i]
+        );
+    }
+
+  }
+
+  public static int CalculateDistance(string s, out string siteToCheck) {
+    siteToCheck = "";
+    // Remove the leading www and similar (they cannot be invalid if the rest of the url is valid)
+    s = wwwRE.Replace(s, "");
+    // Remove the domain parts before the 2nd
+    int pos = s.LastIndexOf('.');
+    if (pos > 0) pos = s.LastIndexOf('.', pos - 1);
+    if (pos > 0) s = s[(pos + 1)..];
+
+    if (s == "discord.com" || s == "discord.gg" || s == "discordapp.com" || s == "discordapp.net") return 0;
+    if (s == "steamcommunity.com" || s == "store.steampowered.com" || s == "steampowered.com") return 0;
+    if (s == "epicgames.com") return 0;
+    int extra = 0;
+    if (s.IndexOf("nitro") != -1 || s.IndexOf("gift") != -1 || s.IndexOf("give") != -1) extra = 100;
+
+    // Remove the last part of the url and any leading w??.
+    if (s.IndexOf('.') != -1) s = s[..s.LastIndexOf('.')];
+
+    // Check how many substrings of discord.com we have in the string
+    int valDiscord = 0;
+    for (int j = 0; j < 7; j++) {
+      for (int k = 1; k < 7 - j; k++) {
+        if (s.IndexOf("discord".Substring(j, k)) != -1) valDiscord += k;
+      }
+    }
+    int valSteam1 = 0;
+    for (int j = 0; j < 7; j++) {
+      for (int k = 1; k < 7 - j; k++) {
+        if (s.IndexOf("steamcommunity".Substring(j, k)) != -1) valSteam1 += k;
+      }
+    }
+    int valSteam2 = 0;
+    for (int j = 0; j < 7; j++) {
+      for (int k = 1; k < 7 - j; k++) {
+        if (s.IndexOf("steampowered".Substring(j, k)) != -1) valSteam2 += k;
+      }
+    }
+    int valEpic = 0;
+    for (int j = 0; j < 7; j++) {
+      for (int k = 1; k < 7 - j; k++) {
+        if (s.IndexOf("epicgames".Substring(j, k)) != -1) valEpic += k;
+      }
+    }
+    int max = valDiscord; siteToCheck = "discord.com";
+    if (valSteam1 > max) { max = valSteam1; siteToCheck = "steamcommunity.com"; }
+    if (valSteam2 > max) { max = valSteam2; siteToCheck = "steampowered.com"; }
+    if (valEpic > max) { max = valEpic; siteToCheck = "epicgames.com"; }
+    return max + extra;
+  }
+
+  public static int GetDamerauLevenshteinDistance(string s, string t) {
+    if (s.IndexOf("app") != -1) s = s.Replace("app", "");
+
+    var bounds = new { Height = s.Length + 1, Width = t.Length + 1 };
+
+    int[,] matrix = new int[bounds.Height, bounds.Width];
+
+    for (int height = 0; height < bounds.Height; height++) { matrix[height, 0] = height; };
+    for (int width = 0; width < bounds.Width; width++) { matrix[0, width] = width; };
+
+    for (int height = 1; height < bounds.Height; height++) {
+      for (int width = 1; width < bounds.Width; width++) {
+        int cost = (s[height - 1] == t[width - 1]) ? 0 : 1;
+        int insertion = matrix[height, width - 1] + 1;
+        int deletion = matrix[height - 1, width] + 1;
+        int substitution = matrix[height - 1, width - 1] + cost;
+
+        int distance = Math.Min(insertion, Math.Min(deletion, substitution));
+
+        if (height > 1 && width > 1 && s[height - 1] == t[width - 2] && s[height - 2] == t[width - 1]) {
+          distance = Math.Min(distance, matrix[height - 2, width - 2] + cost);
+        }
+
+        matrix[height, width] = distance;
+      }
+    }
+
+    return matrix[bounds.Height - 1, bounds.Width - 1];
+  }
+
+
+  internal static async Task CheckMessage(DiscordClient client, MessageCreateEventArgs args) {
+    try {
+      string msg = args.Message.Content.ToLowerInvariant();
+      Match m = linkRE.Match(msg);
+      if (!m.Success) return;
+      string link = m.Groups[1].Value;
+
+      float dist = CalculateDistance(link, out string probableSite);
+      if (dist != 0) {
+        float leven = GetDamerauLevenshteinDistance(link, probableSite);
+        if (link == probableSite) leven = 1;
+        float riskval = dist / (float)Math.Sqrt(leven);
+        if (riskval > 3) {
+          Utils.Log("Removed spam link message from " + args.Author.Username + "\nPossible counterfeit site: " + probableSite + "\noriginal link: " + msg);
+          DiscordMessage warning = await args.Message.Channel.SendMessageAsync("Removed spam link message from " + args.Author.Username + " possible counterfeit site: " + probableSite);
+          await args.Message.DeleteAsync("Spam link from " + args.Author.Username + " @Mod please take care");
+          Utils.DeleteDelayed(10000, warning).Wait();
+        }
+      }
+
+    } catch (Exception ex) {
+      await args.Message.RespondAsync(Utils.GenerateErrorAnswer("CheckSpam.CheckMessage", ex));
+    }
+  }
+}
+

UPBot Code/Program.cs

@@ -70,6 +70,7 @@ static async Task MainAsync(string token, string prefix) {
         lw?.WriteLine("BannedWords");
         lw.Flush();
         discord.MessageCreated += async (s, e) => { await BannedWords.CheckMessage(s, e); };
+        discord.MessageCreated += async (s, e) => { await CheckSpam.CheckMessage(s, e); };
         discord.MessageCreated += AppreciationTracking.ThanksAdded;
 
         CustomCommandsService.LoadCustomCommands();

UPBot Code/Utils.cs

@@ -12,7 +12,7 @@
 /// </summary>
 public static class Utils
 {
-  public const int vmajor = 0, vminor = 1, vbuild = 4;
+  public const int vmajor = 0, vminor = 1, vbuild = 5;
 
 
   /// <summary>
@@ -31,7 +31,7 @@ public static class Utils
   private static DiscordGuild guild;
 
   public static string GetVersion() {
-    return vmajor + "." + vminor + "." + vbuild + "c - 2022/01/09";
+    return vmajor + "." + vminor + "." + vbuild + " - 2022/01/23";
   }
 
   /// <summary>