Improved arcadyan signature

src/binwalk/magic/firmware

@@ -522,6 +522,11 @@
 # Obfuscated Arcadyan firmware
 0x68    string  \x00\xD5\x08                    Obfuscated Arcadyan firmware,
 >0x6B   byte    !0                              invalid signature trailing byte [0x%X],{invalid}
+# None of the known Arcadyan signatures bytes have a NULL byte
+>0      byte    0                               {invalid}
+>1      byte    0                               {invalid}
+>2      byte    0                               {invalid}
+>3      byte    0                               {invalid}
 >0      ubelong x                               signature bytes: 0x%X,
 >0x70   string  !\x00\x00\x00\x00\x00\x00       invalid padding bytes,{invalid}
 >0x70   belong  0x00000000                      see https://github.com/devttys0/wrt120n/deobfuscator

src/binwalk/modules/extractor.py

@@ -562,7 +562,7 @@ class Extractor(Module):
                 except KeyboardInterrupt as e:
                     raise e
                 except Exception as e:
-                    binwalk.core.common.warning("Extractor.execute failed to run internal extractor '%s': %s" % (str(cmd), str(e)))
+                    binwalk.core.common.warning("Internal extractor '%s' failed with exception: '%s'" % (str(cmd), str(e)))
             else:
                 # If not in debug mode, create a temporary file to redirect stdout and stderr to
                 if not binwalk.core.common.DEBUG: