adding support for string features with special characters e.g. '\n'

capa/features/__init__.py

@@ -125,6 +125,10 @@ class String(Feature):
     def __init__(self, value, description=None):
         super(String, self).__init__(value, description=description)
 
+    def get_value_str(self):
+        """ """
+        return repr(self.value).strip("'")
+
 
 class Regex(String):
     def __init__(self, value, description=None):
@@ -194,7 +198,7 @@ class StringFactory(object):
     def __new__(self, value, description=None):
         if value.startswith("/") and (value.endswith("/") or value.endswith("/i")):
             return Regex(value, description=description)
-        return String(value, description=description)
+        return String(str(codecs.decode(value, "unicode_escape")), description=description)
 
 
 class Bytes(Feature):

tests/test_rules.py

@@ -681,6 +681,24 @@ def test_explicit_string_values_int():
     assert (String("0x123") in children) == True
 
 
+def test_string_values_special_characters():
+    rule = textwrap.dedent(
+        """
+        rule:
+            meta:
+                name: test rule
+            features:
+                - or:
+                    - string: hello\\r\\nworld
+                    - string: some\\path
+        """
+    )
+    r = capa.rules.Rule.from_yaml(rule)
+    children = list(r.statement.get_children())
+    assert (String("hello\r\nworld") in children) == True
+    assert (String("some\\path") in children) == True
+
+
 def test_regex_values_always_string():
     rules = [
         capa.rules.Rule.from_yaml(