diff --git a/mirai/misc.py b/mirai/misc.py
index 843852c..2aae500 100644
--- a/mirai/misc.py
+++ b/mirai/misc.py
@@ -4,6 +4,8 @@
 import typing as T
 import random
 from .logger import Protocol
+import os
+import re
 
 def assertOperatorSuccess(result, raise_exception=False, return_as_is=False):
     if "code" in result:
@@ -46,6 +48,21 @@ class ImageType(Enum):
     "friend": r"(?<=/)([0-9a-z]{8})\-([0-9a-z]{4})-([0-9a-z]{4})-([0-9a-z]{4})-([0-9a-z]{12})"
 }
 
+_windows_device_files = (
+    "CON",
+    "AUX",
+    "COM1",
+    "COM2",
+    "COM3",
+    "COM4",
+    "LPT1",
+    "LPT2",
+    "LPT3",
+    "PRN",
+    "NUL",
+)
+_filename_ascii_strip_re = re.compile(r"[^A-Za-z0-9_.-]")
+
 def getMatchedString(regex_result):
     if regex_result:
         return regex_result.string[slice(*regex_result.span())]
@@ -84,4 +101,26 @@ async def warpper(*args, **kwargs):
         except Exception as e:
             Protocol.error(f"protocol method {func.__name__} raised a error: {e.__class__.__name__}")
             raise e
-    return warpper
\ No newline at end of file
+    return warpper
+
+def secure_filename(filename):
+    if isinstance(filename, str):
+        from unicodedata import normalize
+
+        filename = normalize("NFKD", filename).encode("ascii", "ignore")
+        filename = filename.decode("ascii")
+
+    for sep in os.path.sep, os.path.altsep:
+        if sep:
+            filename = filename.replace(sep, " ")
+
+    filename = \
+        str(_filename_ascii_strip_re.sub("", "_".join(filename.split()))).strip("._")
+
+    if (
+        os.name == "nt" and filename and \
+        filename.split(".")[0].upper() in _windows_device_files
+    ):
+        filename = "_" + filename
+
+    return filename
\ No newline at end of file
diff --git a/mirai/session.py b/mirai/session.py
index d56bf6d..763d1ee 100644
--- a/mirai/session.py
+++ b/mirai/session.py
@@ -288,10 +288,10 @@ async def main_entrance(self, run_body, event_context, queue):
     try:
       if isinstance(run_body, dict):
         middlewares = run_body.get("middlewares")
-
-        async_middlewares = []
-        normal_middlewares = []
         if middlewares:
+          async_middlewares = []
+          normal_middlewares = []
+
           for middleware in middlewares:
             if all([
               hasattr(middleware, "__aenter__"),