diff --git a/src/abstractions/audit.service.ts b/src/abstractions/audit.service.ts
new file mode 100644
index 0000000000..0ea1e1fe89
--- /dev/null
+++ b/src/abstractions/audit.service.ts
@@ -0,0 +1,3 @@
+export abstract class AuditService {
+    passwordLeaked: (password: string) => Promise<number>;
+}
diff --git a/src/abstractions/crypto.service.ts b/src/abstractions/crypto.service.ts
index dbf5f0da75..704171f2c8 100644
--- a/src/abstractions/crypto.service.ts
+++ b/src/abstractions/crypto.service.ts
@@ -31,4 +31,5 @@ export abstract class CryptoService {
     decrypt: (cipherString: CipherString, key?: SymmetricCryptoKey, outputEncoding?: string) => Promise<string>;
     decryptFromBytes: (encBuf: ArrayBuffer, key: SymmetricCryptoKey) => Promise<ArrayBuffer>;
     rsaDecrypt: (encValue: string) => Promise<string>;
+    sha1: (password: string) => Promise<string>;
 }
diff --git a/src/services/audit.service.ts b/src/services/audit.service.ts
new file mode 100644
index 0000000000..f91da9c76d
--- /dev/null
+++ b/src/services/audit.service.ts
@@ -0,0 +1,26 @@
+import { CryptoService } from '../abstractions/crypto.service';
+
+const PwnedPasswordsApi = 'https://api.pwnedpasswords.com/range/';
+
+export class AuditService {
+
+    constructor(private cryptoService: CryptoService) {
+    }
+
+    async passwordLeaked(password: string): Promise<number> {
+        const hash = (await this.cryptoService.sha1(password)).toUpperCase();
+
+        const response = await fetch(PwnedPasswordsApi + hash.substr(0, 5));
+        const leakedHashes = await response.text();
+
+        const hashEnding = hash.substr(5);
+
+        const match = leakedHashes
+            .split(/\r?\n/)
+            .find((v) => {
+                return v.split(':')[0] === hashEnding;
+            });
+
+        return match ? parseInt(match.split(':')[1], 10) : 0;
+    }
+}
diff --git a/src/services/crypto.service.ts b/src/services/crypto.service.ts
index e6ad642574..93dbcd3b5c 100644
--- a/src/services/crypto.service.ts
+++ b/src/services/crypto.service.ts
@@ -452,6 +452,17 @@ export class CryptoService implements CryptoServiceAbstraction {
         return b64DecValue;
     }
 
+    async sha1(password: string): Promise<string> {
+        const hash = await Crypto.subtle.digest(
+            {
+                name: 'SHA-1',
+            },
+            UtilsService.fromUtf8ToArray(password),
+        );
+
+        return UtilsService.fromBufferToHex(hash);
+    }
+
     // Helpers
 
     private async aesEncrypt(plainValue: ArrayBuffer, key: SymmetricCryptoKey): Promise<EncryptedObject> {
diff --git a/src/services/utils.service.ts b/src/services/utils.service.ts
index 359a743a91..a1e900e761 100644
--- a/src/services/utils.service.ts
+++ b/src/services/utils.service.ts
@@ -125,6 +125,14 @@ export class UtilsService implements UtilsServiceAbstraction {
         return decodeURIComponent(escape(encodedString));
     }
 
+    // Source: Frxstrem, https://stackoverflow.com/questions/40031688/javascript-arraybuffer-to-hex
+    static fromBufferToHex(buffer: ArrayBuffer): string {
+        return Array.prototype.map.call(
+            new Uint8Array(buffer),
+            (x: number) => ('00' + x.toString(16)).slice(-2),
+        ).join('');
+    }
+
     static getHostname(uriString: string): string {
         if (uriString == null) {
             return null;