diff --git a/app/common/fileutil.py b/app/common/fileutil.py
index 60650ff..43a3768 100644
--- a/app/common/fileutil.py
+++ b/app/common/fileutil.py
@@ -44,15 +44,19 @@ def _get_file_mime(file_path):
 
 def _is_perf_file(file_path):
     f = get_file(file_path)
-    for line in f:
-        if (line[0] == '#'):
-            continue
-        r = event_regexp.search(line)
-        if r:
-            f.close()
-            return True
-        f.close()
+    try:
+        for line in f:
+            if line and line[0] == '#':
+                continue
+            r = event_regexp.search(line)
+            if r:
+                return True
+            return False
+    except Exception:
         return False
+    finally:
+        f.close()
+    return False
 
 
 def get_file(file_path):
diff --git a/tests/test_fileutil.py b/tests/test_fileutil.py
new file mode 100644
index 0000000..5b1026f
--- /dev/null
+++ b/tests/test_fileutil.py
@@ -0,0 +1,18 @@
+import os
+import tempfile
+from app import config
+from app.common.fileutil import _is_perf_file
+
+
+def test_is_perf_file_unreadable_bytes():
+    # Create a temporary file in PROFILE_DIR containing invalid UTF-8 bytes
+    with tempfile.NamedTemporaryFile(dir=config.PROFILE_DIR, mode="wb", delete=False) as f:
+        f.write(b"\xff\xfe\xfd\x00\x98\xa1\xb2\xc3")
+        temp_path = f.name
+
+    try:
+        # Should return False without raising UnicodeDecodeError
+        assert _is_perf_file(temp_path) is False
+    finally:
+        if os.path.exists(temp_path):
+            os.remove(temp_path)