diff --git a/app/Services/HardeningService.php b/app/Services/HardeningService.php
index 2ac01dd..d9206ab 100644
--- a/app/Services/HardeningService.php
+++ b/app/Services/HardeningService.php
@@ -52,7 +52,26 @@ class HardeningService
         $fw = FirewallTool::for($os);
 
         // Shell CONDITIONS (exit 0 = true); `false` where the host lacks the tool.
-        $f2bInst = $pm ? $pm->isInstalledTest('fail2ban') : 'false';
+        // "Installed" is read CONSISTENTLY with Fail2banService/FirewallTool: the package
+        // manager (dpkg ^ii / rpm), OR the client binary on PATH, OR the service already
+        // running — ANY one proves the component is present. So a fail2ban/ufw installed
+        // from source or left in dpkg `rc` (config-only) state no longer reads as "nicht
+        // installiert" while its own live panel reports it active. A component can never be
+        // active without being installed, so this only removes FALSE negatives.
+        $anyOf = fn (array $tests): string => '('.implode(' || ', array_filter($tests)).')';
+
+        $f2bActive = 'systemctl is-active --quiet fail2ban';
+        $f2bInst = $anyOf([
+            $pm?->isInstalledTest('fail2ban'),
+            'command -v fail2ban-client >/dev/null 2>&1',
+            $f2bActive,
+        ]);
+        $fwInst = $anyOf([
+            $pm?->isInstalledTest($os->firewallTool === 'firewalld' ? 'firewalld' : 'ufw'),
+            $fw->installedTest(),
+            $fw->activeTest(),
+        ]);
+
         $auInst = $pm ? $pm->isInstalledTest($os->packageManager === 'dnf' ? 'dnf-automatic' : 'unattended-upgrades') : 'false';
         $auActive = match ($os->packageManager) {
             'apt' => 'apt-config dump APT::Periodic::Unattended-Upgrade 2>/dev/null | grep -q \'"1"\'',
@@ -60,9 +79,11 @@ class HardeningService
             default => 'false',
         };
 
+        // NOTE the space after each `$(` that precedes a `(`: `$( (` is a command
+        // substitution of a subshell, whereas `$((` would be ARITHMETIC expansion.
         $cmd = 'sshd -T 2>/dev/null | grep -iE "^(permitrootlogin|passwordauthentication) "; '
-            .'echo "fail2ban $('.$f2bInst.' && echo 1 || echo 0) $(systemctl is-active --quiet fail2ban && echo active || echo inactive)"; '
-            .'echo "firewall $('.$fw->installedTest().' && echo 1 || echo 0) $('.$fw->activeTest().' && echo active || echo inactive)"; '
+            .'echo "fail2ban $( '.$f2bInst.' && echo 1 || echo 0) $('.$f2bActive.' && echo active || echo inactive)"; '
+            .'echo "firewall $( '.$fwInst.' && echo 1 || echo 0) $('.$fw->activeTest().' && echo active || echo inactive)"; '
             .'echo "autoupdate $('.$auInst.' && echo 1 || echo 0) $('.$auActive.' && echo active || echo inactive)"';
 
         $res = $this->fleet->runPrivileged($server, $cmd);
diff --git a/tests/Feature/HardeningServiceTest.php b/tests/Feature/HardeningServiceTest.php
new file mode 100644
index 0000000..31b38e8
--- /dev/null
+++ b/tests/Feature/HardeningServiceTest.php
@@ -0,0 +1,69 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Models\Server;
+use App\Services\FirewallService;
+use App\Services\FleetService;
+use App\Services\HardeningService;
+use App\Support\Os\OsDetector;
+use App\Support\Os\OsProfile;
+use Mockery;
+use Tests\TestCase;
+
+class HardeningServiceTest extends TestCase
+{
+    protected function tearDown(): void
+    {
+        Mockery::close();
+        parent::tearDown();
+    }
+
+    private function debianProfile(): OsProfile
+    {
+        return new OsProfile(
+            family: 'debian',
+            id: 'debian',
+            prettyName: 'Debian GNU/Linux 13',
+            packageManager: 'apt',
+            firewallTool: 'ufw',
+            serviceManager: 'systemd',
+            available: ['apt-get', 'dpkg', 'systemctl', 'fail2ban-client', 'ufw'],
+        );
+    }
+
+    /**
+     * The checklist must agree with the fail2ban/firewall panels: a component counts as
+     * installed when the package manager lists it (^ii/rpm) OR its binary is on PATH OR
+     * the service is running — not via dpkg `^ii` alone (the false "nicht installiert").
+     */
+    public function test_installed_probe_falls_back_to_binary_and_service(): void
+    {
+        $os = $this->debianProfile();
+
+        $detector = Mockery::mock(OsDetector::class);
+        $detector->shouldReceive('detect')->andReturn($os);
+
+        $captured = '';
+        $fleet = Mockery::mock(FleetService::class);
+        $fleet->shouldReceive('runPrivileged')
+            ->andReturnUsing(function ($server, $cmd) use (&$captured) {
+                $captured = $cmd;
+
+                // fail2ban running from a source/`rc` install: present + active.
+                return ['ok' => true, 'output' => "fail2ban 1 active\nfirewall 1 active\nautoupdate 0 inactive"];
+            });
+
+        $service = new HardeningService($fleet, Mockery::mock(FirewallService::class), $detector);
+
+        $rows = $service->state(new Server);
+
+        // fail2ban installed-probe gains the binary fallback (was dpkg ^ii only — the bug).
+        $this->assertStringContainsString('command -v fail2ban-client', $captured);
+        // firewall installed-probe gains the package-manager fallback (was command -v only).
+        $this->assertStringContainsString('dpkg -l ufw', $captured);
+
+        $f2b = collect($rows)->firstWhere('key', 'fail2ban');
+        $this->assertTrue($f2b['featureOn'], 'fail2ban active must read as on');
+    }
+}