Practical security for servers and apps: patching, fail2ban, audits with Lynis and rkhunter, and vulnerability checks.
Security
The best hardware wallet in 2026 depends on how you use crypto: Ledger for the widest coin support, Trezor for open source, Keystone for air-gapped QR signing, SafePal on a budget, Coldcard Q for Bitcoin only. Current models, prices and the setup rules that matter more than the device.
Security
two critical bugs landed on 21 October 2026: php2shell in PHP and a Brotli RCE in Node.js. Here's how to find every affected server and container, patch it, and check whether anyone got in first.
Security
In this article you will learn a couple of methods on how to fix Fail2ban High Memory Usage problem. There may be several reasons for Fail2ban consumption a very large amount of memory (in my case it was about 2,5 GB!). I will list some of the reasons and
Security
In this Lynis tutorial you will learn: * How to install Lynis tool in CentOS and Debian Linux. * Perform Linux security audit with Lynis Lynis Tool for Linux Audit Lynis is a free and open source security auditing tool for Linux, mac OS, and other systems based on UNIX. The tool
Security
Zimbra Fail2ban Setup How to install and configure Fail2ban for Zimbra mail server on CentOS. Fail2Ban is an intrusion prevention software framework that protects computer servers from brute-force attacks. Install Fail2ban on CentOS 7: Ensure your system is up to date and install the EPEL repository: # yum update # yum
Security
How do I scan for viruses with ClamAV? At first you have to update the virus definitions with: sudo freshclam Then you can scan for viruses. clamscan OPTIONS File/Folder If necessary start with root permissions: sudo clamscan. Examples: * To check all files on the computer, displaying the name of
Security
How to fix OpenVAS error: Login failed. OMP service is down Just run two commands from Linux terminal: # openvasmd stop # openvasmd start
Security
Your server appearing pretty slow could be many things from wrong configs, scripts and dodgy hardware – but sometimes it could be because someone is flooding your server with traffic known as DoS ( Denial of Service ) or DDoS ( Distributed Denial of Service ). Denial-of-service attack (DoS attack) or Distributed Denial-
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Fail2ban Unban Single Host run: iptables -L For example we need to unban 10.110.11.16 Then get the actual jails list: fail2ban-client status Unban command is: fail2ban-client set jailname unbanip m.y.i.p For unban 10.110.11.16 IP from asterisk jail run command:
Security
Install Rkhunter (Rootkit Hunter) in RHEL, CentOS Rkhunter is rootkit scanner for Linux systems. This tool scans for rootkits, backdoors and local exploits by running tests like: – MD5 hash compare – Look for default files used by rootkits – Wrong file permissions for binaries – Look for suspected strings in LKM and KLD
Security
DDoS-Deflate $CONF not found. In Debian and Ubuntu If you have error: DDoS-Deflate version 0.6 Copyright (C) 2005, Zaf <[email protected]> $CONF not found. Change #!/bin/sh in first line of file: /usr/local/ddos/ddos.sh to #!/bin/bash There are two more