diff --git a/osu.Game.Tests/Visual/Online/TestSceneImageProxying.cs b/osu.Game.Tests/Visual/Online/TestSceneImageProxying.cs
new file mode 100644
index 0000000000..0cf6fec6f0
--- /dev/null
+++ b/osu.Game.Tests/Visual/Online/TestSceneImageProxying.cs
@@ -0,0 +1,47 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using NUnit.Framework;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics;
+using osu.Framework.Platform;
+using osu.Game.Graphics.Containers.Markdown;
+
+namespace osu.Game.Tests.Visual.Online
+{
+    public partial class TestSceneImageProxying : OsuTestScene
+    {
+        [Resolved]
+        private GameHost host { get; set; } = null!;
+
+        [Test]
+        public void TestExternalImageLink()
+        {
+            AddStep("load image", () => Child = new OsuMarkdownContainer
+            {
+                RelativeSizeAxes = Axes.Both,
+                Text = "![](https://github.com/ppy/osu-wiki/blob/master/wiki/Announcement_messages/img/notification.png?raw=true)",
+            });
+        }
+
+        [Test]
+        public void TestLocalImageLink()
+        {
+            AddStep("load image", () => Child = new OsuMarkdownContainer
+            {
+                RelativeSizeAxes = Axes.Both,
+                Text = "![](https://osu.ppy.sh/help/wiki/shared/news/banners/monthly-beatmapping-contest.png)",
+            });
+        }
+
+        [Test]
+        public void TestInvalidImageLink()
+        {
+            AddStep("load image", () => Child = new OsuMarkdownContainer
+            {
+                RelativeSizeAxes = Axes.Both,
+                Text = "![](https://this-site-does-not-exist.com/img.png)",
+            });
+        }
+    }
+}
diff --git a/osu.Game/Audio/PreviewTrackManager.cs b/osu.Game/Audio/PreviewTrackManager.cs
index 1d710e6395..81564cc2e8 100644
--- a/osu.Game/Audio/PreviewTrackManager.cs
+++ b/osu.Game/Audio/PreviewTrackManager.cs
@@ -6,9 +6,10 @@ using osu.Framework.Audio;
 using osu.Framework.Audio.Track;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
-using osu.Framework.IO.Stores;
 using osu.Framework.Logging;
 using osu.Game.Beatmaps;
+using osu.Game.Online;
+using osu.Game.Online.API;
 
 namespace osu.Game.Audio
 {
@@ -28,9 +29,9 @@ namespace osu.Game.Audio
         }
 
         [BackgroundDependencyLoader]
-        private void load(AudioManager audioManager)
+        private void load(AudioManager audioManager, IAPIProvider api)
         {
-            trackStore = audioManager.GetTrackStore(new OnlineStore());
+            trackStore = audioManager.GetTrackStore(new OsuOnlineStore(api.APIEndpointUrl));
         }
 
         /// <summary>
diff --git a/osu.Game/Graphics/Containers/Markdown/OsuMarkdownImage.cs b/osu.Game/Graphics/Containers/Markdown/OsuMarkdownImage.cs
index 10207dd389..ff7df18f00 100644
--- a/osu.Game/Graphics/Containers/Markdown/OsuMarkdownImage.cs
+++ b/osu.Game/Graphics/Containers/Markdown/OsuMarkdownImage.cs
@@ -17,5 +17,8 @@ namespace osu.Game.Graphics.Containers.Markdown
         {
             TooltipText = linkInline.Title;
         }
+
+        protected override ImageContainer CreateImageContainer(string url)
+            => base.CreateImageContainer($@"https://osu.ppy.sh/media-url?url={url}");
     }
 }
diff --git a/osu.Game/Online/OsuOnlineStore.cs b/osu.Game/Online/OsuOnlineStore.cs
new file mode 100644
index 0000000000..c3e81c503f
--- /dev/null
+++ b/osu.Game/Online/OsuOnlineStore.cs
@@ -0,0 +1,31 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using System;
+using osu.Framework.IO.Stores;
+using osu.Framework.Logging;
+
+namespace osu.Game.Online
+{
+    public class OsuOnlineStore : OnlineStore
+    {
+        private readonly string apiEndpointUrl;
+
+        public OsuOnlineStore(string apiEndpointUrl)
+        {
+            this.apiEndpointUrl = apiEndpointUrl;
+        }
+
+        protected override string GetLookupUrl(string url)
+        {
+            // add leading dot to avoid matching hosts named "<anything>ppy.sh"
+            if (!Uri.TryCreate(url, UriKind.Absolute, out Uri? uri) || !uri.Host.EndsWith(@".ppy.sh", StringComparison.OrdinalIgnoreCase))
+            {
+                Logger.Log($@"Blocking resource lookup from external website: {url}", LoggingTarget.Network, LogLevel.Important);
+                return string.Empty;
+            }
+
+            return url;
+        }
+    }
+}
diff --git a/osu.Game/OsuGame.cs b/osu.Game/OsuGame.cs
index 08960e3ebb..943e9b6c4e 100644
--- a/osu.Game/OsuGame.cs
+++ b/osu.Game/OsuGame.cs
@@ -29,6 +29,7 @@ using osu.Framework.Input;
 using osu.Framework.Input.Bindings;
 using osu.Framework.Input.Events;
 using osu.Framework.Input.Handlers.Tablet;
+using osu.Framework.IO.Stores;
 using osu.Framework.Localisation;
 using osu.Framework.Logging;
 using osu.Framework.Platform;
@@ -824,6 +825,8 @@ namespace osu.Game
 
         protected override Container CreateScalingContainer() => new ScalingContainer(ScalingMode.Everything);
 
+        protected override OnlineStore CreateOnlineStore() => new OsuOnlineStore(CreateEndpoints().APIEndpointUrl);
+
         #region Beatmap progression
 
         private void beatmapChanged(ValueChangedEvent<WorkingBeatmap> beatmap)
diff --git a/osu.Game/OsuGameBase.cs b/osu.Game/OsuGameBase.cs
index b028280774..df3334eae8 100644
--- a/osu.Game/OsuGameBase.cs
+++ b/osu.Game/OsuGameBase.cs
@@ -277,7 +277,7 @@ namespace osu.Game
             dependencies.CacheAs(Storage);
 
             var largeStore = new LargeTextureStore(Host.Renderer, Host.CreateTextureLoaderStore(new NamespacedResourceStore<byte[]>(Resources, @"Textures")));
-            largeStore.AddTextureSource(Host.CreateTextureLoaderStore(new OnlineStore()));
+            largeStore.AddTextureSource(Host.CreateTextureLoaderStore(CreateOnlineStore()));
             dependencies.Cache(largeStore);
 
             dependencies.CacheAs(LocalConfig);