diff --git a/pallets/unified-accounts/src/tests.rs b/pallets/unified-accounts/src/tests.rs
index 30f3c40eb2..d6e3fd6203 100644
--- a/pallets/unified-accounts/src/tests.rs
+++ b/pallets/unified-accounts/src/tests.rs
@@ -184,83 +184,120 @@ fn account_claim_should_work() {
 }
 
 #[test]
-fn account_claim_should_not_work() {
+fn account_default_claim_works() {
     ExtBuilder::default().build().execute_with(|| {
-        // invald signature
-        assert_noop!(
-            UnifiedAccounts::claim_evm_address(
-                RuntimeOrigin::signed(ALICE),
-                UnifiedAccounts::eth_address(&bob_secret()),
-                get_evm_signature(&BOB, &bob_secret())
-            ),
-            Error::<TestRuntime>::InvalidSignature
+        let alice_default_evm =
+            <TestRuntime as Config>::DefaultAccountMapping::into_h160(ALICE.into());
+
+        // claim default account
+        assert_ok!(UnifiedAccounts::claim_default_evm_address(
+            RuntimeOrigin::signed(ALICE)
+        ));
+        System::assert_last_event(RuntimeEvent::UnifiedAccounts(
+            crate::Event::AccountClaimed {
+                account_id: ALICE.clone(),
+                evm_address: alice_default_evm.clone(),
+            },
+        ));
+
+        // check UnifiedAddressMapper's mapping works
+        assert_eq!(
+            <UnifiedAccounts as UnifiedAddressMapper<_>>::to_h160(&ALICE),
+            Some(alice_default_evm)
         );
+        assert_eq!(
+            <UnifiedAccounts as UnifiedAddressMapper<_>>::to_account_id(&alice_default_evm),
+            Some(ALICE)
+        );
+
+        // should not allow to claim afterwards
         assert_noop!(
             UnifiedAccounts::claim_evm_address(
                 RuntimeOrigin::signed(ALICE),
-                UnifiedAccounts::eth_address(&bob_secret()),
+                UnifiedAccounts::eth_address(&alice_secret()),
                 get_evm_signature(&ALICE, &alice_secret())
             ),
-            Error::<TestRuntime>::InvalidSignature
+            Error::<TestRuntime>::AlreadyMapped
         );
+    });
+}
 
+#[test]
+fn replay_attack_should_not_be_possible() {
+    ExtBuilder::default().build().execute_with(|| {
+        let alice_eth = UnifiedAccounts::eth_address(&alice_secret());
+        let alice_signature = get_evm_signature(&ALICE, &alice_secret());
+
+        // alice claim her eth address first
         assert_ok!(UnifiedAccounts::claim_evm_address(
             RuntimeOrigin::signed(ALICE),
-            UnifiedAccounts::eth_address(&alice_secret()),
-            get_evm_signature(&ALICE, &alice_secret())
+            alice_eth,
+            alice_signature
         ));
-        // AccountId already mapped
+
+        // bob intercepted alice signature and tries to perform
+        // replay attack to claim alice eth address as his own,
+        // this should fail.
         assert_noop!(
             UnifiedAccounts::claim_evm_address(
-                RuntimeOrigin::signed(ALICE),
-                UnifiedAccounts::eth_address(&alice_secret()),
-                get_evm_signature(&ALICE, &alice_secret())
+                RuntimeOrigin::signed(BOB),
+                alice_eth,
+                alice_signature
             ),
             Error::<TestRuntime>::AlreadyMapped
         );
-        // eth address already mapped
+    });
+}
+
+#[test]
+fn frontrun_attack_should_not_be_possible() {
+    ExtBuilder::default().build().execute_with(|| {
+        let alice_eth = UnifiedAccounts::eth_address(&alice_secret());
+        let alice_signature = get_evm_signature(&ALICE, &alice_secret());
+
+        // bob intercepted alice signature and tries to perform
+        // frontrun attack to claim alice eth address as his own
+        // this should fail with InvalidSignature.
         assert_noop!(
             UnifiedAccounts::claim_evm_address(
                 RuntimeOrigin::signed(BOB),
-                UnifiedAccounts::eth_address(&alice_secret()),
-                get_evm_signature(&ALICE, &alice_secret())
+                alice_eth,
+                alice_signature
             ),
-            Error::<TestRuntime>::AlreadyMapped
+            Error::<TestRuntime>::InvalidSignature
         );
+
+        // alice can claim her eth address
+        assert_ok!(UnifiedAccounts::claim_evm_address(
+            RuntimeOrigin::signed(ALICE),
+            alice_eth,
+            alice_signature
+        ));
     });
 }
 
 #[test]
-fn account_default_claim_works() {
+fn connecting_mapped_accounts_should_not_work() {
     ExtBuilder::default().build().execute_with(|| {
-        let alice_default_evm =
-            <TestRuntime as Config>::DefaultAccountMapping::into_h160(ALICE.into());
-
-        // claim default account
-        assert_ok!(UnifiedAccounts::claim_default_evm_address(
-            RuntimeOrigin::signed(ALICE)
-        ));
-        System::assert_last_event(RuntimeEvent::UnifiedAccounts(
-            crate::Event::AccountClaimed {
-                account_id: ALICE.clone(),
-                evm_address: alice_default_evm.clone(),
-            },
-        ));
+        // connect ALICE accounts
+        connect_accounts(&ALICE, &alice_secret());
 
-        // check UnifiedAddressMapper's mapping works
-        assert_eq!(
-            <UnifiedAccounts as UnifiedAddressMapper<_>>::to_h160(&ALICE),
-            Some(alice_default_evm)
-        );
-        assert_eq!(
-            <UnifiedAccounts as UnifiedAddressMapper<_>>::to_account_id(&alice_default_evm),
-            Some(ALICE)
+        // AccountId already mapped
+        // ALICE attempts to connect another evm address
+        assert_noop!(
+            UnifiedAccounts::claim_evm_address(
+                RuntimeOrigin::signed(ALICE),
+                UnifiedAccounts::eth_address(&bob_secret()),
+                get_evm_signature(&BOB, &bob_secret())
+            ),
+            Error::<TestRuntime>::AlreadyMapped
         );
 
-        // should not allow to claim afterwards
+        // eth address already mapped
+        // BOB attempts to connect alice_eth that is already mapped
         assert_noop!(
             UnifiedAccounts::claim_evm_address(
-                RuntimeOrigin::signed(ALICE),
+                RuntimeOrigin::signed(BOB),
                 UnifiedAccounts::eth_address(&alice_secret()),
                 get_evm_signature(&ALICE, &alice_secret())
             ),