refactor: use with for file open

nxc/modules/nanodump.py

@@ -189,14 +189,13 @@ class NXCModule:
                 except Exception as e:
                     self.context.log.fail(f"[OPSEC] Error deleting lsass.dmp file on dir {self.remote_tmp_dir}: {e}")
 
-            fh = open(filename, "r+b")
-            fh.seek(0)
-            fh.write(b"\x4d\x44\x4d\x50")
-            fh.seek(4)
-            fh.write(b"\xa7\x93")
-            fh.seek(6)
-            fh.write(b"\x00\x00")
-            fh.close()
+            with open(filename, "r+b") as fh: # needs the "r+b", not "rb" like below
+                fh.seek(0)
+                fh.write(b"\x4d\x44\x4d\x50")
+                fh.seek(4)
+                fh.write(b"\xa7\x93")
+                fh.seek(6)
+                fh.write(b"\x00\x00")
 
             with open(filename, "rb") as dump:
                 try: