Well making a trojan is very easy now-a-days by using tools such as lostdoor, poisonivy, etc. But the real challenge is to pass the trojan a system's antivirus. Here's a post on the same. Here we used a virtual application creator, Xenocode, which is famous for creating portable applications. It kinda encrypts our trojan and further if we bind our trojan with another exe, it is bound to be executed by the victim. I'll surely post on binding in my next post.
The encrypted trojan does not match with the virus definitions in the antivirus and hence is rendered undetected.
Make Trojan Fully Undetectable (FUD) using Xenocode
You can make your own trojan using LostDoor. But the problem with the so formed trojan is it being detected by almost all AV softwares. We know that after learning to make your own trojan, the next thing you must've exhausted your bandwidth searching for is: "How to make a Trojan undetectable?" Well here is the answer.
First of all you'll have to download Xenocode (Never heard of it? Google it. This may help you. http://www.xenocode.com/Technology/)
Xenocode is a set of application virtualization and portable application creation technologies developed by Code Systems Corporation. Applications are packed into single executable files that can be executed instantly on any Windows desktop (so called "portable apps"). The technology therefore emulates only the operation system features that are necessary for the application to run. Applications can be deployed using existing infrastructure, software deployment tools, the web or USB keys. The virtualized application runs independently from other software that is installed on the host PC so there are no conflicts between different versions or DLL files.
Well, reading the above introduction must've got you acquainted you with xenocode application. You might be wondering, how this application will help you in making your Trojan undetectable.
Xenocode creates a virtual operating system for processing the files you have virtualized and hence it completely overwrites your code. As you may know, AV softwares use virus signatures to identify viruses. There are ways in which you can make a trojan undetectable by modifying the Hex code, but it is very tedious. Using xenocode alleviates the pain to a negligible level. The only pain you will have is to grab a full version of the application. Keep in mind that trial version xenocode does not create virtual applications. When you will click on the build button, it will prompt you to purchase license. We hope you understand what we mean to say implicitly.
After you download xenocode, give your trojan as the input. Now click on the build button and then specify the location where the output file must be saved. The so formed file is your undetecable Trojan. You can try scanning it with your local AV. Or if you wanna see how far you've gone, upload the file on No Virus Thanks. It will provide you results after scannig your file with 20 different AV. Our score for this test was 0 outa 20. No AV detected it and the file still works fine.
Xenocode download link