Show HN: TheProtector – Linux Bash script for the paranoid admin on a budget
I spent the past year building this in my spare time because I got tired of enterprise security tools that cost $50K/year and don't understand Linux.
TheProtector is a comprehensive security monitoring tool that actually runs on the systems we use (Linux) instead of being a Windows-first afterthought. Built it entirely on a $500 laptop because I believe good security shouldn't require unlimited budgets.
Features: - Real-time process, network, and file monitoring - YARA malware detection with custom rules - eBPF kernel monitoring (when available) - Behavioral baseline establishment and anomaly detection - Active threat response (blocks IPs, kills processes, quarantines files) - Anti-evasion detection for rootkits and advanced threats - Honeypots for attack detection - Web dashboard for monitoring - Single bash script, no complex installation
The tagline is "not perfect but better than most" because I'm tired of security vendors claiming their tools are flawless. This actually works, costs $0, and you can read every line of code.
I know bash isn't the sexy choice for security tools, but it runs everywhere, has zero dependencies, and most Linux admins can read/modify it. Sometimes boring technology that works is better than fancy technology that doesn't.
It's designed for the intersection of "paranoid about security" and "don't have enterprise budgets" - which describes most of us actually running Linux systems.
GitHub: https://github.com/IHATEGIVINGAUSERNAME/theProtector
Been running it on my own systems for months. Catches the stuff that matters and doesn't flood you with false positives. If you hate expensive security theater as much as I do, might be worth a look.
Open to feedback, especially from folks who know more about this stuff than I do.
Thanks, IHATEGIVINGAUSERNAME (yes, I really do hate giving usernames)
At first glance I questioned your choice of bash over something like Python, but you're right - bash is everywhere and every competent Linux admin knows how to use it. There's a zillion unprotected Linux servers out there where this would be very handy.
In terms of next steps, it might be worth documenting more about the notification framework and some simple examples of how we might use it. I can see you've mentioned integrations with email, Slack and webhooks in the tech paper, but I can't spot anything about how to use them
Congratulations on a really worthy project
...except on systems like Alpine Linux and other such minimal distributions.
Here's what you should know:
The Good: It's a comprehensive monitoring solution that actually catches real threats. The YARA integration, eBPF monitoring, and honeypot features are impressive for a bash script.
Security Issues:
1. Command injection in process monitoring - Initially looked like a vulnerability because the code uses xargs basename on process names, which seemed dangerous. However, process names from ps output are already sanitized by the kernel (limited to 15 chars, no shell metacharacters executed).
2. Executing Python scripts from /tmp as root - Real privilege escalation vulnerability. Ghost Sentinel writes to world-writable /tmp then executes as root. Any local user can overwrite the file between write and execute to gain root. Trivial to exploit with inotify or loop, 100% reliable. Turns any compromised service account into root access. Fix: use root-owned directory instead of /tmp.
Email Configuration - Gmail will block direct server emails. Install msmtp and configure it with your Gmail app password (not regular password) to get theProtector to use msmtp's mail command:
Uninstall TheProtector: Auto-update concerns: The script does NOT auto-update. self_update() only runs when you explicitly execute ./the_protector.sh updatePerformance note: On resource-constrained VPS instances, set ENABLE_EBPF=false and MAX_FIND_DEPTH=1
I'm deploying a patched version this week. The creator spent a year on this and it shows - the eBPF/YARA integration is impressive. They should set up GitHub Sponsors or a donation link. It's better than many commercial solutions I've seen.
I'm not sure what this is referring to. You can easily create a binary named ' (single quote, a shell meta character) and it will show up in ps (and /proc/pid/cmdline and /proc/pid/status) as a single quote. If you name a binary with a control character, it will show up in ps as ? (a shell metacharacter), and in /proc/$pid/cmdline and /proc/$pid/status as the control character itself (I named a binary as the single ASCII character 7, bell, and catting /proc/$pid/{cmdline,status} plays the as interpreted by the terminal program).
Recent versions of ls display these directory entries quoted for select-and-paste ease as:
This was with kernel 5.14 and procps-ng-3.3.17.Formatted by ls, the ^G file can be given to xargs, and the terminal plays a bell, but the single quote filename can not:
Being able to null-byte delimit the input to xargs may make a difference here.Anyway, you can't trust the content of what ps shows as the commandline pointing to an actual existing binary. The command line isn't always absolute. The best way to find the binary is probably by examining where the symlink /proc/$pid/exe points to, and getting the basename off of that, but that is not guaranteed to be shell-safe either, so YMMV.
- author attribution (in fact, a mockery is made of it)
- qualified independent security review and endorsement
- designs justifying irrational decisions such as unilateral superuser execution
- any sort of testing, validation or significant documentation of code functionality
- steps to undo whatever this does (since anything is possible, as all liability is explicitely disavowed)
This is not meant to discourage development, but such software should have a clear an EXPERIMENTAL disclaimer and not purport to secure anything; primum non nocere.
https://github.com/IHATEGIVINGAUSERNAME/theProtector/blob/ma...
"TheProtector is a comprehensive security monitoring tool that actually runs on the systems we use (Linux) instead of being a Windows-first afterthought. Built it entirely on a $500 laptop because I believe good security shouldn't require unlimited budgets." After reviewing the code it doesn't seem very comprehensive. As some others have pointed out it appears to be mostly AI-generated. Again, as a learning opportunity this isn't a bad exercise, but I also probably wouldn't brag about it being comparable to tools that were made by teams of people who are likely far more knowledgeable when it comes to designing such tools.
"Been running it on my own systems for months. Catches the stuff that matters and doesn't flood you with false positives. If you hate expensive security theater as much as I do, might be worth a look." I should also probably address the elephant in the room: Your github account is only 2 days old (as of this writing). Additionally the initial commit to the repository was made on July 23rd, 2025. Based on the commit history (and based on the files that were committed) it looks like this was created with AI in the span of a couple days.
I'm sure a 'security-minded' individual such as yourself sees the problem here: a monolithic script from some random person on the internet purporting to have developed something to help secure my system... I wouldn't touch it with a 10-foot pole.
Something about this post stinks to me. Smells like somone trying to phish for installs. Seems like something an intelligence agency would do: post something like this in several places hoping somone runs it.
Also, you're calling this TheProtector, but internally it seems to be called ghost sentinel?
> local update_url="https://raw[dot]githubusercontent[dot]com/your-repo/ghost-se..."
One thing though: I can imagine you being rather anonymous (no real name, new HN account, new GitHub account) might make people a bit nervous around a security tool. You probably have good reasons for that, but if not.. you might want to reconsider and take credit?
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