(Backdoor Part 2)At last..Payload CANT BE DETECTED..!!

Why its cant be detected,where at first I encode it with *.exe then I manipulate it using ruby to be embedded inside *.vbs extension and below is the result from virus total.

File name:payload.vbs
Submission date:2011-05-23 17:32:43 (UTC)
Current status:finished
Result:0/ 42 (0.0%)

Additional information
MD5 : 8e54f3b36507c7c3f4a80ee336e367ae
SHA1 : ed8ba524a09494dcd7f86dbe5859339706264911
SHA256: 3ff926d2c6dfcee6443de3f0f0916a5ce1d1ccebe6f55399fcb8118758fc041d
ssdeep: 6144:kgwFOmxCAB1vR5CGikL/xz+fk+8yXRruNG63b/IjRuePX7k49TQ7rBlLRc3aT+ch:vwEmw
AvvR5CbS/9R+86RruNbLgduePXI
File size : 297145 bytes
First seen: 2011-05-23 17:32:43
Last seen : 2011-05-23 17:32:43
TrID:
Unknown!
sigcheck:
publisher....: n/a
copyright....: n/a
product......: n/a
description..: n/a
original name: n/a
internal name: n/a
file version.: n/a
comments.....: n/a
signers......: -
signing date.: -
verified.....: Unsigned