diff --git a/spec/beef/core/main/handlers/browserdetails_spec.rb b/spec/beef/core/main/handlers/browserdetails_spec.rb
new file mode 100644
index 000000000..2d3bc0599
--- /dev/null
+++ b/spec/beef/core/main/handlers/browserdetails_spec.rb
@@ -0,0 +1,144 @@
+RSpec.describe BeEF::Core::Handlers::BrowserDetails do
+  let(:config) { BeEF::Core::Configuration.instance }
+  let(:session_id) { 'test_session_123' }
+  let(:mock_request) do
+    double('Request',
+           ip: '127.0.0.1',
+           referer: 'http://example.com',
+           env: { 'HTTP_USER_AGENT' => 'Mozilla/5.0' })
+  end
+  let(:data) do
+    {
+      'beefhook' => session_id,
+      'request' => mock_request,
+      'results' => {
+        'browser.name' => 'FF',
+        'browser.version' => '91.0',
+        'browser.window.hostname' => 'example.com',
+        'browser.window.hostport' => '80'
+      }
+    }
+  end
+
+  before do
+    allow(config).to receive(:get).and_call_original
+    allow(config).to receive(:get).with('beef.dns_hostname_lookup').and_return(false)
+    allow(config).to receive(:get).with('beef.extension.network.enable').and_return(false)
+    allow(config).to receive(:get).with('beef.http.websocket.enable').and_return(false)
+    allow(BeEF::Filters).to receive(:is_valid_hook_session_id?).and_return(true)
+    allow(BeEF::Core::Models::HookedBrowser).to receive(:where).and_return([])
+    allow(BeEF::Core::Logger.instance).to receive(:register)
+    allow(BeEF::Core::GeoIp.instance).to receive(:enabled?).and_return(false)
+    # Stub NetworkHost if it exists, otherwise stub the constant
+    if defined?(BeEF::Core::Models::NetworkHost)
+      allow(BeEF::Core::Models::NetworkHost).to receive(:create)
+    else
+      stub_const('BeEF::Core::Models::NetworkHost', double('NetworkHost', create: nil))
+    end
+    allow(BeEF::Core::AutorunEngine::Engine.instance).to receive(:find_and_run_all_matching_rules_for_zombie)
+  end
+
+  describe '#initialize' do
+    it 'initializes with data and calls setup' do
+      expect_any_instance_of(described_class).to receive(:setup)
+      described_class.new(data)
+    end
+  end
+
+  describe '#err_msg' do
+    let(:handler) do
+      instance = described_class.allocate
+      instance.instance_variable_set(:@data, data)
+      instance
+    end
+
+    it 'calls print_error with prefixed message' do
+      expect(handler).to receive(:print_error).with('[Browser Details] test error')
+      handler.err_msg('test error')
+    end
+  end
+
+  describe '#get_param' do
+    let(:handler) do
+      # Create handler but prevent full setup execution
+      instance = described_class.allocate
+      instance.instance_variable_set(:@data, data)
+      instance
+    end
+
+    it 'returns value when key exists in hash' do
+      result = handler.get_param(data['results'], 'browser.name')
+      expect(result).to eq('FF')
+    end
+
+    it 'returns nil when key does not exist' do
+      result = handler.get_param(data['results'], 'nonexistent')
+      expect(result).to be_nil
+    end
+
+    it 'returns nil when query is not a hash' do
+      result = handler.get_param('not a hash', 'key')
+      expect(result).to be_nil
+    end
+
+    it 'converts value to string' do
+      result = handler.get_param({ 'key' => 123 }, 'key')
+      expect(result).to eq('123')
+    end
+  end
+
+  describe '#setup' do
+    it 'validates session id' do
+      invalid_data = data.dup
+      invalid_data['beefhook'] = 'invalid'
+      allow(BeEF::Filters).to receive(:is_valid_hook_session_id?).with('invalid').and_return(false)
+      expect { described_class.new(invalid_data) }.not_to raise_error
+    end
+
+    it 'skips setup if browser already registered' do
+      existing_browser = double('HookedBrowser', session: session_id)
+      allow(BeEF::Core::Models::HookedBrowser).to receive(:where).and_return([existing_browser])
+      expect(BeEF::Core::Models::HookedBrowser).not_to receive(:new)
+      described_class.new(data)
+    end
+
+    it 'creates new hooked browser when not registered' do
+      allow(BeEF::Core::Models::HookedBrowser).to receive(:where).and_return([])
+      allow(BeEF::Filters).to receive(:is_valid_browsername?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_browserversion?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_ip?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_browserstring?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_cookies?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_osname?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_hwname?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_date_stamp?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_pagetitle?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_url?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_pagereferrer?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_hostname?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_port?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_browser_plugins?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_system_platform?).and_return(true)
+      allow(BeEF::Filters).to receive(:nums_only?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_yes_no?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_memory?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_gpu?).and_return(true)
+      allow(BeEF::Filters).to receive(:is_valid_cpu?).and_return(true)
+      allow(BeEF::Filters).to receive(:alphanums_only?).and_return(true)
+      allow(BeEF::Core::Models::BrowserDetails).to receive(:set)
+      allow(BeEF::Core::Constants::Browsers).to receive(:friendly_name).and_return('Firefox')
+      zombie = double('HookedBrowser', id: 1, ip: '127.0.0.1')
+      allow(zombie).to receive(:firstseen=)
+      allow(zombie).to receive(:domain=)
+      allow(zombie).to receive(:port=)
+      allow(zombie).to receive(:httpheaders=)
+      allow(zombie).to receive(:httpheaders).and_return('{}')
+      allow(zombie).to receive(:save!)
+      # Mock JSON.parse for proxy detection
+      allow(JSON).to receive(:parse).with('{}').and_return({})
+      allow(BeEF::Core::Models::HookedBrowser).to receive(:new).and_return(zombie)
+      described_class.new(data)
+      expect(BeEF::Core::Models::HookedBrowser).to have_received(:new).with(ip: '127.0.0.1', session: session_id)
+    end
+  end
+end