diff --git a/lib/SP/Providers/Auth/Ldap/LdapBase.php b/lib/SP/Providers/Auth/Ldap/LdapBase.php
index 133acb5f..6d4e7495 100644
--- a/lib/SP/Providers/Auth/Ldap/LdapBase.php
+++ b/lib/SP/Providers/Auth/Ldap/LdapBase.php
@@ -122,7 +122,7 @@ abstract class LdapBase implements LdapInterface
             return LdapUtil::getGroupName($this->ldapParams->getGroup()) ?: '';
         }
 
-        return $this->ldapParams->getGroup();
+        return $this->ldapParams->getGroup() ?? '';
     }
 
     /**
diff --git a/lib/SP/Providers/Auth/Ldap/LdapMsAds.php b/lib/SP/Providers/Auth/Ldap/LdapMsAds.php
index bf0aa0ea..1de4576e 100644
--- a/lib/SP/Providers/Auth/Ldap/LdapMsAds.php
+++ b/lib/SP/Providers/Auth/Ldap/LdapMsAds.php
@@ -64,7 +64,7 @@ final class LdapMsAds extends LdapBase
             $attributes = $this->ldapParams->getFilterGroupAttributes();
         }
 
-        return '(&(|' . LdapUtil::getAttributesForFilter($attributes, $this->getGroupDn()) . ')' . $filter . ')';
+        return sprintf("(&(|%s)%s)", LdapUtil::getAttributesForFilter($attributes, $this->getGroupDn()), $filter);
     }
 
     /**
@@ -90,11 +90,11 @@ final class LdapMsAds extends LdapBase
             $attributes = $this->ldapParams->getFilterUserAttributes();
         }
 
-        return '(&(|'
-               . LdapUtil::getAttributesForFilter($attributes, $userLogin)
-               . ')'
-               . $this->getUserObjectFilter()
-               . ')';
+        return sprintf(
+            "(&(|%s)%s)",
+            LdapUtil::getAttributesForFilter($attributes, $userLogin),
+            $this->getUserObjectFilter()
+        );
     }
 
     /**
@@ -196,9 +196,7 @@ final class LdapMsAds extends LdapBase
             $attributes = $this->ldapParams->getFilterGroupAttributes();
         }
 
-        return '(|'
-               . LdapUtil::getAttributesForFilter($attributes, $this->getGroupDn())
-               . ')';
+        return sprintf("(|%s)", LdapUtil::getAttributesForFilter($attributes, $this->getGroupDn()));
     }
 
     protected function pickServer(): string
diff --git a/lib/SP/Providers/Auth/Ldap/LdapStd.php b/lib/SP/Providers/Auth/Ldap/LdapStd.php
index 680a7baf..ebb8809b 100644
--- a/lib/SP/Providers/Auth/Ldap/LdapStd.php
+++ b/lib/SP/Providers/Auth/Ldap/LdapStd.php
@@ -63,7 +63,7 @@ final class LdapStd extends LdapBase
             $attributes = $this->ldapParams->getFilterGroupAttributes();
         }
 
-        return '(&(|' . LdapUtil::getAttributesForFilter($attributes, $this->getGroupDn()) . ')' . $filter . ')';
+        return sprintf("(&(|%s)%s)", LdapUtil::getAttributesForFilter($attributes, $this->getGroupDn()), $filter);
     }
 
     /**
@@ -91,7 +91,7 @@ final class LdapStd extends LdapBase
 
         $filter = $this->getUserObjectFilter();
 
-        return '(&(|' . LdapUtil::getAttributesForFilter($attributes, $userLogin) . ')' . $filter . ')';
+        return sprintf("(&(|%s)%s)", LdapUtil::getAttributesForFilter($attributes, $userLogin), $filter);
     }
 
     /**
@@ -104,17 +104,15 @@ final class LdapStd extends LdapBase
         // los grupos del usuario
         if (empty($this->ldapParams->getGroup())
             || $this->ldapParams->getGroup() === '*'
-            || in_array($this->getGroupDn(), $groupsDn, true)) {
+            || in_array($this->getGroupDn(), $groupsDn, true)
+        ) {
             $this->eventDispatcher->notifyEvent(
                 'ldap.check.group',
                 new Event(
                     $this,
                     EventMessage::factory()
                                 ->addDescription(__u('User in group verified'))
-                                ->addDetail(
-                                    __u('User'),
-                                    $userDn
-                                )
+                                ->addDetail(__u('User'), $userDn)
                                 ->addDetail(__u('Group'), $this->ldapParams->getGroup())
                 )
             );
@@ -144,21 +142,26 @@ final class LdapStd extends LdapBase
                     $this,
                     EventMessage::factory()
                                 ->addDescription(__u('User does not belong to the group'))
-                                ->addDetail(
-                                    __u('User'),
-                                    $userDn
-                                )
+                                ->addDetail(__u('User'), $userDn)
                                 ->addDetail(__u('Group'), $this->getGroupFromParams())
-                                ->addDetail(
-                                    'LDAP FILTER',
-                                    $filter
-                                )
+                                ->addDetail('LDAP FILTER', $filter)
                 )
             );
 
             return false;
         }
 
+        $this->eventDispatcher->notifyEvent(
+            'ldap.check.group',
+            new Event(
+                $this,
+                EventMessage::factory()
+                            ->addDescription(__u('User in group verified'))
+                            ->addDetail(__u('User'), $userDn)
+                            ->addDetail(__u('Group'), $this->getGroupFromParams())
+            )
+        );
+
         return true;
     }
 
@@ -174,8 +177,14 @@ final class LdapStd extends LdapBase
             return $this->getUserObjectFilter();
         }
 
-        return '(&(cn=' . $groupName . ')' . '(|(memberUid=' . $member . ')(member=' . $member . ')(uniqueMember=' . $member . '))' .
-               $this->getGroupObjectFilter() . ')';
+        return sprintf(
+            '(&(cn=%s)(|(memberUid=%s)(member=%s)(uniqueMember=%s))%s)',
+            $groupName,
+            $member,
+            $member,
+            $member,
+            $this->getGroupObjectFilter()
+        );
     }
 
     /**
diff --git a/tests/SP/Providers/Auth/Ldap/LdapMsAdsTest.php b/tests/SP/Providers/Auth/Ldap/LdapMsAdsTest.php
index f3bc4421..d355beea 100644
--- a/tests/SP/Providers/Auth/Ldap/LdapMsAdsTest.php
+++ b/tests/SP/Providers/Auth/Ldap/LdapMsAdsTest.php
@@ -44,11 +44,11 @@ use SP\Tests\UnitaryTestCase;
 class LdapMsAdsTest extends UnitaryTestCase
 {
 
-    private LdapConnectionInterface|MockObject        $ldapConnection;
-    private LdapActionsInterface|MockObject|LdapMsAds $ldapActions;
-    private EventDispatcherInterface|MockObject       $eventDispatcher;
-    private LdapMsAds                                 $ldap;
-    private LdapParams                                $ldapParams;
+    private LdapConnectionInterface|MockObject  $ldapConnection;
+    private LdapActionsInterface|MockObject     $ldapActions;
+    private EventDispatcherInterface|MockObject $eventDispatcher;
+    private LdapMsAds                           $ldap;
+    private LdapParams                          $ldapParams;
 
     public static function groupDataProvider(): array
     {
diff --git a/tests/SP/Providers/Auth/Ldap/LdapStdTest.php b/tests/SP/Providers/Auth/Ldap/LdapStdTest.php
new file mode 100644
index 00000000..5373af42
--- /dev/null
+++ b/tests/SP/Providers/Auth/Ldap/LdapStdTest.php
@@ -0,0 +1,382 @@
+<?php
+/*
+ * sysPass
+ *
+ * @author nuxsmin
+ * @link https://syspass.org
+ * @copyright 2012-2023, Rubén Domínguez nuxsmin@$syspass.org
+ *
+ * This file is part of sysPass.
+ *
+ * sysPass is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * sysPass is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with sysPass.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+namespace SP\Providers\Auth\Ldap;
+
+use PHPUnit\Framework\MockObject\MockObject;
+use SP\Core\Events\EventDispatcherInterface;
+use SP\Core\Exceptions\SPException;
+use SP\Domain\Auth\Ports\LdapActionsInterface;
+use SP\Domain\Auth\Ports\LdapConnectionInterface;
+use SP\Tests\UnitaryTestCase;
+
+/**
+ * Class LdapStdTest
+ *
+ * @group unitary
+ */
+class LdapStdTest extends UnitaryTestCase
+{
+
+    private LdapConnectionInterface|MockObject  $ldapConnection;
+    private LdapActionsInterface|MockObject     $ldapActions;
+    private EventDispatcherInterface|MockObject $eventDispatcher;
+    private LdapStd                             $ldap;
+    private LdapParams                          $ldapParams;
+
+    public static function groupDataProvider(): array
+    {
+        return [
+            [''],
+            ['*'],
+            ['cn=TestGroup,dc=groups,dc=syspass,dc=org']
+        ];
+    }
+
+    /**
+     * @throws LdapException
+     */
+    public function testConnect()
+    {
+        $user = self::$faker->userName;
+        $password = self::$faker->password;
+
+        $this->ldapConnection->expects(self::once())->method('connect')->with($user, $password);
+
+        $this->ldap->connect($user, $password);
+    }
+
+    /**
+     * @throws LdapException
+     */
+    public function testConnectWithNull()
+    {
+        $this->ldapConnection->expects(self::once())->method('connect')->with(null, null);
+
+        $this->ldap->connect();
+    }
+
+    /**
+     * @dataProvider groupDataProvider()
+     * @throws LdapException
+     */
+    public function testIsUserInGroup(string $group)
+    {
+        $this->ldapParams->setGroup($group);
+
+        $userDn = 'cn=TestUser,dc=syspass,dc=org';
+        $userLogin = self::$faker->userName;
+        $groupsDn = [
+            'cn=TestGroup,dc=groups,dc=syspass,dc=org'
+        ];
+
+        $this->eventDispatcher
+            ->expects(self::once())
+            ->method('notifyEvent')
+            ->with('ldap.check.group', self::anything());
+
+        $out = $this->ldap->isUserInGroup($userDn, $userLogin, $groupsDn);
+
+        self::assertTrue($out);
+    }
+
+    /**
+     * @throws LdapException
+     */
+    public function testIsUserInGroupWithSearchGroupDn()
+    {
+        $this->ldapParams->setGroup('TestGroup');
+
+        $userDn = 'cn=TestUser,dc=syspass,dc=org';
+        $userLogin = self::$faker->userName;
+        $groupsDn = [
+            'cn=TestGroup,dc=groups,dc=syspass,dc=org'
+        ];
+
+        $this->ldapActions->expects(self::once())
+                          ->method('searchGroupsDn')
+                          ->with($this->ldap->getGroupObjectFilter())
+                          ->willReturn($groupsDn);
+
+        $this->eventDispatcher
+            ->expects(self::once())
+            ->method('notifyEvent')
+            ->with('ldap.check.group', self::anything());
+
+        $out = $this->ldap->isUserInGroup($userDn, $userLogin, $groupsDn);
+
+        self::assertTrue($out);
+    }
+
+    /**
+     * @throws LdapException
+     */
+    public function testIsUserInGroupWithCheckFilter()
+    {
+        $this->ldapParams->setGroup('TestGroup');
+
+        $userDn = 'cn=TestUser,dc=syspass,dc=org';
+        $userLogin = self::$faker->userName;
+        $groupDn = 'cn=TestGroup,dc=groups,dc=syspass,dc=org';
+
+        $this->ldapActions->expects(self::exactly(1))
+                          ->method('searchGroupsDn')
+                          ->with($this->ldap->getGroupObjectFilter())
+                          ->willReturnOnConsecutiveCalls([], [], [$groupDn]);
+
+        $groupsFilter = '(&(cn=TestGroup)(|(memberUid=cn=TestUser,dc=syspass,dc=org)(member=cn=TestUser,dc=syspass,dc=org)(uniqueMember=cn=TestUser,dc=syspass,dc=org))(|(objectClass=groupOfNames)(objectClass=groupOfUniqueNames)(objectClass=group)))';
+
+        $this->ldapActions
+            ->expects(self::once())
+            ->method('getObjects')
+            ->with($groupsFilter, ['dn']);
+
+        $this->eventDispatcher
+            ->expects(self::once())
+            ->method('notifyEvent')
+            ->with('ldap.check.group', self::anything());
+
+        $out = $this->ldap->isUserInGroup($userDn, $userLogin, []);
+
+        self::assertTrue($out);
+    }
+
+    /**
+     * @throws LdapException
+     */
+    public function testIsUserInGroupWithCheckFilterAndZeroResults()
+    {
+        $this->ldapParams->setGroup('TestGroup');
+
+        $userDn = 'cn=TestUser,dc=syspass,dc=org';
+        $userLogin = self::$faker->userName;
+        $groupDn = 'cn=TestGroup,dc=groups,dc=syspass,dc=org';
+
+        $this->ldapActions->expects(self::exactly(1))
+                          ->method('searchGroupsDn')
+                          ->with($this->ldap->getGroupObjectFilter())
+                          ->willReturnOnConsecutiveCalls([], [], [$groupDn]);
+
+        $groupsFilter = '(&(cn=TestGroup)(|(memberUid=cn=TestUser,dc=syspass,dc=org)(member=cn=TestUser,dc=syspass,dc=org)(uniqueMember=cn=TestUser,dc=syspass,dc=org))(|(objectClass=groupOfNames)(objectClass=groupOfUniqueNames)(objectClass=group)))';
+
+        $this->ldapActions
+            ->expects(self::once())
+            ->method('getObjects')
+            ->with($groupsFilter, ['dn'])
+            ->willReturn(['count' => 0]);
+
+        $this->eventDispatcher
+            ->expects(self::once())
+            ->method('notifyEvent')
+            ->with('ldap.check.group', self::anything());
+
+        $out = $this->ldap->isUserInGroup($userDn, $userLogin, [$groupDn]);
+
+        self::assertFalse($out);
+    }
+
+    /**
+     * @throws SPException
+     */
+    public function testGetGroupMembershipIndirectFilter()
+    {
+        $groupDn = 'cn=TestGroup,dc=groups,dc=syspass,dc=org';
+        $this->ldapParams->setGroup('TestGroup');
+
+        $this->ldapActions->expects(self::once())
+                          ->method('searchGroupsDn')
+                          ->with($this->ldap->getGroupObjectFilter())
+                          ->willReturn([$groupDn]);
+
+        $out = $this->ldap->getGroupMembershipIndirectFilter();
+
+        $expected = sprintf(
+            "(&(|%s)%s)",
+            LdapUtil::getAttributesForFilter(LdapStd::DEFAULT_FILTER_GROUP_ATTRIBUTES, $groupDn),
+            '(|(objectClass=inetOrgPerson)(objectClass=person)(objectClass=simpleSecurityObject))'
+        );
+
+        self::assertEquals($expected, $out);
+    }
+
+    /**
+     * @throws SPException
+     */
+    public function testGetGroupMembershipIndirectFilterWithEmptyGroup()
+    {
+        $this->ldapActions->expects(self::never())
+                          ->method('searchGroupsDn');
+
+        $out = $this->ldap->getGroupMembershipIndirectFilter();
+        $expected = '(|(objectClass=inetOrgPerson)(objectClass=person)(objectClass=simpleSecurityObject))';
+
+        self::assertEquals($expected, $out);
+    }
+
+    /**
+     * @throws SPException
+     */
+    public function testGetGroupMembershipIndirectFilterWithAttributes()
+    {
+        $groupDn = 'cn=TestGroup,dc=groups,dc=syspass,dc=org';
+        $this->ldapParams->setGroup('TestGroup');
+        $this->ldapParams->setFilterGroupAttributes(['testAttribute']);
+
+        $this->ldapActions->expects(self::once())
+                          ->method('searchGroupsDn')
+                          ->with($this->ldap->getGroupObjectFilter())
+                          ->willReturn([$groupDn]);
+
+        $out = $this->ldap->getGroupMembershipIndirectFilter();
+
+        $expected = sprintf(
+            "(&(|%s)%s)",
+            LdapUtil::getAttributesForFilter(['testAttribute'], $groupDn),
+            '(|(objectClass=inetOrgPerson)(objectClass=person)(objectClass=simpleSecurityObject))'
+        );
+
+        self::assertEquals($expected, $out);
+    }
+
+    public function testGetUserDnFilter()
+    {
+        $user = self::$faker->userName;
+
+        $out = $this->ldap->getUserDnFilter($user);
+
+        $expected = sprintf(
+            "(&(|%s)%s)",
+            LdapUtil::getAttributesForFilter(LdapMsAds::DEFAULT_FILTER_USER_ATTRIBUTES, $user),
+            '(|(objectClass=inetOrgPerson)(objectClass=person)(objectClass=simpleSecurityObject))'
+        );
+
+        self::assertEquals($expected, $out);
+    }
+
+    public function testGetUserDnFilterWithAttributes()
+    {
+        $this->ldapParams->setFilterUserAttributes(['memberOf']);
+        $user = self::$faker->userName;
+
+        $out = $this->ldap->getUserDnFilter($user);
+
+        $expected = sprintf(
+            "(&(|%s)%s)",
+            LdapUtil::getAttributesForFilter(['memberOf'], $user),
+            '(|(objectClass=inetOrgPerson)(objectClass=person)(objectClass=simpleSecurityObject))'
+        );
+
+        self::assertEquals($expected, $out);
+    }
+
+    public function testGetGroupObjectFilter()
+    {
+        $out = $this->ldap->getGroupObjectFilter();
+        $expected = '(|(objectClass=groupOfNames)(objectClass=groupOfUniqueNames)(objectClass=group))';
+
+        self::assertEquals($expected, $out);
+    }
+
+    public function testGetGroupObjectFilterWithFilter()
+    {
+        $this->ldapParams->setFilterGroupObject('test');
+
+        $out = $this->ldap->getGroupObjectFilter();
+
+        self::assertEquals('test', $out);
+    }
+
+    public function testGetServer()
+    {
+        self::assertEquals($this->ldapParams->getServer(), $this->ldap->getServer());
+    }
+
+    public function testGetGroupMembershipDirectFilter()
+    {
+        $this->ldapParams->setGroup('TestGroup');
+        $out = $this->ldap->getGroupMembershipDirectFilter();
+
+        $expected = sprintf(
+            '(&(cn=%s)(|(memberUid=%s)(member=%s)(uniqueMember=%s))%s)',
+            'TestGroup',
+            '*',
+            '*',
+            '*',
+            '(|(objectClass=groupOfNames)(objectClass=groupOfUniqueNames)(objectClass=group))'
+        );
+
+        self::assertEquals($expected, $out);
+    }
+
+    public function testGetGroupMembershipDirectFilterWithUser()
+    {
+        $user = 'TestUser';
+        $this->ldapParams->setGroup('TestGroup');
+        $out = $this->ldap->getGroupMembershipDirectFilter($user);
+
+        $expected = sprintf(
+            '(&(cn=%s)(|(memberUid=%s)(member=%s)(uniqueMember=%s))%s)',
+            'TestGroup',
+            $user,
+            $user,
+            $user,
+            '(|(objectClass=groupOfNames)(objectClass=groupOfUniqueNames)(objectClass=group))'
+        );
+
+        self::assertEquals($expected, $out);
+    }
+
+    public function testGetGroupMembershipDirectFilterWithoutGroup()
+    {
+        $user = 'TestUser';
+        $out = $this->ldap->getGroupMembershipDirectFilter($user);
+
+        $expected = '(|(objectClass=inetOrgPerson)(objectClass=person)(objectClass=simpleSecurityObject))';
+
+        self::assertEquals($expected, $out);
+    }
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->ldapConnection = $this->createMock(LdapConnectionInterface::class);
+        $this->ldapActions = $this->createMock(LdapActionsInterface::class);
+        $this->eventDispatcher = $this->createMock(EventDispatcherInterface::class);
+
+        $this->ldapParams = new LdapParams(
+            self::$faker->domainName,
+            LdapTypeEnum::ADS,
+            self::$faker->userName,
+            self::$faker->password
+        );
+
+        $this->ldap = new LdapStd(
+            $this->ldapConnection,
+            $this->ldapActions,
+            $this->ldapParams,
+            $this->eventDispatcher
+        );
+    }
+}