diff --git a/apps/browser/src/platform/services/phishing-detection.service.ts b/apps/browser/src/platform/services/phishing-detection.service.ts
new file mode 100644
index 00000000000..71c10817e90
--- /dev/null
+++ b/apps/browser/src/platform/services/phishing-detection.service.ts
@@ -0,0 +1,32 @@
+import { Utils } from "@bitwarden/common/platform/misc/utils";
+
+import { BrowserApi } from "../browser/browser-api";
+
+export class PhishingDetectionService {
+  private static knownPhishingDomains = new Set();
+
+  static checkUrl(url: string): boolean {
+    const domain = Utils.getDomain(url);
+    return PhishingDetectionService.knownPhishingDomains.has(domain);
+  }
+
+  // @TODO: We need to flesh this out to actually use the real data that comes from the server.
+  // This method can be run using a background worker once a day or at a similar interval.
+  static updateKnownPhishingDomains(): void {
+    PhishingDetectionService.loadMockedData();
+  }
+
+  // @TODO: This can be remove once we implement the real code.
+  private static loadMockedData() {
+    PhishingDetectionService.knownPhishingDomains.add("google.com");
+    PhishingDetectionService.knownPhishingDomains.add("atlassian.net");
+  }
+
+  async getActiveUrl(): Promise<string> {
+    const win = await BrowserApi.getCurrentWindow();
+    const currentWindow = await BrowserApi.tabsQuery({ windowId: win.id, active: true });
+
+    // @TODO: Account for cases with no active windows.
+    return currentWindow[0].url;
+  }
+}