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Enhancing your server security against ransomware deployment protocols starts with robust authentication methods. Passwordless authentication using FIDO2 security keys significantly reduces attack surfaces by eliminating password-based vulnerabilities.
You Should Know:
- Setting Up FIDO2 Security Key for RDP on Windows
To enable FIDO2-based authentication for Remote Desktop Protocol (RDP), follow these steps: -
Enable Windows Hello for Business (Group Policy or Intune):
Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Windows\System" -Name "AllowDomainPINLogon" -Value 1
2. Configure RDP to Use FIDO2:
reg add "HKLM\SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services" /v "fAllowToGetHelp" /t REG_DWORD /d 1 /f
3. Enforce Network Level Authentication (NLA):
Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Terminal Server\WinStations\RDP-Tcp" -Name "UserAuthentication" -Value 1
2. Linux Server Hardening with FIDO2 (PAM Module)
For Linux systems, integrate FIDO2 via `libfido2` and pam_u2f:
1. Install dependencies:
sudo apt install libfido2-dev libssl-dev pam-u2f
2. Configure PAM:
sudo mkdir -p /etc/ual sudo pamu2fcfg > /etc/ual/u2f_keys
3. Add to `/etc/pam.d/sshd`:
auth required pam_u2f.so authfile=/etc/ual/u2f_keys
3. Verifying FIDO2 Key Enrollment
Check enrolled keys on Windows:
Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\NgcPin"
On Linux:
sudo cat /etc/ual/u2f_keys
4. Mitigating Ransomware via FIDO2
- Disable legacy NTLM:
Set-ItemProperty -Path "HKLM:\SYSTEM\CurrentControlSet\Control\Lsa" -Name "LmCompatibilityLevel" -Value 5
- Audit RDP logins:
Get-WinEvent -LogName "Microsoft-Windows-TerminalServices-RemoteConnectionManager/Operational" | Format-List
What Undercode Say
FIDO2 keys render credential stuffing and phishing obsolete. Combine this with:
– Linux: Fail2Ban (sudo apt install fail2ban) and kernel hardening (sysctl -w kernel.kptr_restrict=2).
– Windows: Constrained Language Mode ($ExecutionContext.SessionState.LanguageMode = "ConstrainedLanguage").
– Network: Segment RDP behind a VPN (WireGuard: wg-quick up wg0).
Expected Output:
A server resistant to ransomware lateral movement, with authentication logs showing only FIDO2-based access:
Event ID 1149: User "admin" authenticated via FIDO2 security key.
Reference: Microsoft FIDO2 RDP Guide
References:
Reported By: Villepaivinen Ransomwaredeploymentprotocol – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
