Guides tagged “security”
Step-by-step MdmHost guides about security, sorted A-Z.
193 guides · page 6 of 10
Lock down SSH on a Linux VPS: a complete checklist
A step-by-step SSH hardening checklist for Linux VPS and WHM servers: keys only, no root password login, firewall limits by IP, brute-force bans and safe testing.
Locked out by your firewall? How to get back into your VPS
If a firewall rule blocked SSH, you can still reach your server through the browser console in your VPS provider's control panel. Disable the firewall, fix the rule and turn it back on safely.
Make iptables rules survive a reboot
iptables rules live in memory and disappear on reboot. Save them with netfilter-persistent on Debian and Ubuntu or iptables-services on AlmaLinux and Rocky Linux.
Malware Scanning on Linux: Configuring ClamAV for Web Root Protection
Install ClamAV on a Linux VPS, tune it for large web directories, scan your web root for malware and schedule daily scans with a systemd timer.
Malware Scanning on Linux: Rootkit Detection and System Integrity Checks
Install rkhunter, chkrootkit and AIDE on your Linux VPS to detect hidden rootkits, trojaned binaries and unauthorised file changes before they spread.
Malware Scanning: Integrating Virus Scans into Automated Update Cycles
Wire malware scanning into your update cycle so every security patch is followed by a virus scan. Covers ClamAV on Linux and Defender on Windows.
Manage CageFS as root: enable users, add tools and update the skeleton
Root guide to CageFS on CloudLinux: enable or disable it per user, list caged users, add commands to the cage, update and remount the skeleton and fix common errors.
Manage several SSH keys for different servers
Keep separate SSH keys for different servers, clients or devices, tell SSH which key to use per host with IdentityFile and IdentitiesOnly, name keys clearly, rotate them and remove old keys from authorized_keys.
Manage shell access for cPanel accounts in WHM: jailed vs normal (root guide)
Decide which cPanel users get SSH, choose between jailed shell, normal shell and CageFS, enable or disable shell per account in WHM, and keep shell access secure.
Manage Windows Defender Firewall on Windows Server with PowerShell
Create, list, restrict and remove Windows Defender Firewall rules on a Windows VPS using the GUI and PowerShell, including limiting RDP to your IP and logging drops.
Microsoft Defender basics on Windows Server
Check Defender is running, update signatures, scan from PowerShell, and use exclusions only where a vendor recommends them.
Migrate iptables rules to nftables
Move an existing iptables firewall to native nftables. Check whether you run iptables-nft or legacy, export with iptables-save, translate the rules, test them and switch the boot service.
Network Hardening: Monitoring for Unauthorized Port Scans on the VPS
Learn how to monitor port scans on a VPS, log the source addresses that probe your server, and block repeat offenders automatically on Linux and Windows.
Open and close ports in CSF (TCP_IN, TCP_OUT, UDP_IN, UDP_OUT)
Edit the CSF port lists to open a port for a new service, close ports you do not use, and restrict a port such as SSH to trusted IPs on a cPanel/WHM server.
Open ports with UFW: single ports, ranges and trusted IPs
Open TCP and UDP ports in UFW, allow port ranges, limit access to one IP or subnet, label rules with comments and confirm everything with ufw status numbered.
Password protect a site or folder with Nginx basic auth
Add a username and password prompt to a whole site, a staging copy or an admin folder with Nginx basic auth, and let trusted IPs through without a password.
Password-protect a directory in DirectAdmin
Protect a folder or staging site with a user name and password using DirectAdmin's Password Protected Directories, manage users and avoid common login loops.
Password-protect a directory or website in Plesk
Add HTTP basic authentication to a folder or a whole site in Plesk with Password-Protected Directories, manage users and protect staging sites and admin areas.
Password-protect a folder with cPanel Directory Privacy
Add a username and password prompt to any folder of your website with cPanel Directory Privacy, ideal for staging sites, wp-admin or private downloads.
Port forwarding and masquerading with firewalld
Forward a port to another local port or to a different host with firewalld, enable masquerading so replies find their way back, then test and make the rules permanent.
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