DenyHosts is a script intended to be run by Linux system administrators to help thwart SSH server attacks (also known as dictionary based attacks and brute force attacks).
Best Tools For Security
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It scans log files (e.g. /var/log/apache/error_log) and bans IPs that show the malicious signs -- too many password failures, seeking for exploits, etc

online tool that you can use to check any website’s header status.

Open-source tests of web browser privacy.
Static analysis at ludicrous speed.

Static code analyzer for Infrastructure as Code

Scan git repos (or files) for secrets using regex and entropy 🔑

Identify vulnerabilities in running containers, images, hosts and repositories

A collection of awesome penetration testing and offensive cybersecurity resources.

Mariana Trench is a security focused static analysis platform targeting Android.

Clean Code starts in your IDE

Community curated list of templates for the nuclei engine to find security vulnerabilities in applications.