Forbid _HumbugBox prefixed classes

src/Rules/ClassForbiddenNameCheck.php

@@ -20,6 +20,7 @@ class ClassForbiddenNameCheck
 		'Rector' => 'RectorPrefix',
 		'PHP-Scoper' => '_PhpScoper',
 		'PHPUnit' => 'PHPUnitPHAR',
+		'Box' => '_HumbugBox',
 	];
 
 	public function __construct(private Container $container)

tests/PHPStan/Rules/Classes/ExistingClassInClassExtendsRuleTest.php

@@ -121,6 +121,11 @@ public function testPhpstanInternalClass(): void
 				62,
 				'This is most likely unintentional. Did you mean to type \SebastianBergmann\Diff\Exception?',
 			],
+			[
+				'Referencing prefixed Box class: _HumbugBox02f3b3909847\AClass.',
+				73,
+				$tip,
+			],
 		]);
 	}
 

tests/PHPStan/Rules/Classes/data/phpstan-internal-class.php

@@ -62,3 +62,13 @@ class Baz extends \_PhpScoper19ae93be897e\AClass
 class BazBar extends \PHPUnitPHAR\SebastianBergmann\Diff\Exception
 {}
 
+namespace _HumbugBox02f3b3909847; // mimicks a prefixed class, as generated by Box
+
+class AClass {
+	const Test = 1;
+}
+
+namespace TestHumbugInternalClass;
+
+class FooBar extends \_HumbugBox02f3b3909847\AClass
+{}