Show HN: TheProtector – Linux Bash script for the paranoid admin on a budget

I love this implementation approach.

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

As someone who runs production services but isn't a full-time sysadmin, I evaluated this script before thinking about deploying it.

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:

  # Install
  sudo apt-get install msmtp msmtp-mta
  
  # Configure ~/.msmtprc (for root since script runs as root)
  sudo tee /root/.msmtprc << 'EOF'
  defaults
  auth           on
  tls            on
  tls_trust_file /etc/ssl/certs/ca-certificates.crt
  account        gmail
  host           smtp.gmail.com
  port           587
  from           your-email@gmail.com
  user           your-email@gmail.com
  password       your-app-password
  account default : gmail
  EOF
  
  sudo chmod 600 /root/.msmtprc

  # Remove cron job
  crontab -l | grep -v ghost_sentinel | crontab -
  
  # Remove systemd timer (if installed)
  sudo systemctl disable ghost-sentinel.timer 2>/dev/null
  
  # Remove logs and data
  sudo rm -rf /var/log/ghost-sentinel

Performance 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.

This cannot conscientiously be called a security tool, as it lacks:

- 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.

"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." You should have written it as a learning opportunity. To think you can replace such tools seems rather arrogant -- Experienced professionals with decades of experience worked on them. You're just 1 person, and it seems like you may be new.

"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.

I would probably delete the self_update function[0] if I were to use this, otherwise this is cool!

https://github.com/IHATEGIVINGAUSERNAME/theProtector/blob/ma...

Neat, but isn't packing all this stuff into a bash script overkill? You can pretty easily install and configure some good tools (i.e. crowdsec, rkhunter, ssh tarpit or whatever) to cover each of the categories rather than have a bunch of half-measures.

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..."

Congratulations on your release! That packs a lot of functionality in a surprisingly small and readable (and thus auditable) shell script. Great work!

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?

The tech paper is LLM trash. Doesn’t bode well for the code, not just because it’s a gigantic bash script..

Would love to see the prompts used. I can tell from the formatting etc this is AI built, nothing wrong with that.

"Built by thelotus over a year of free time. Maintained by thelotus. Given away free because expensive security theater is stupid." Who / what is the lotus?

This is great. I'm currently trying to use Linux more due to Recall but in terms of security I'm just not sure what I'm doing most of the time. I suppose I should go read a book about it. Any suggestions on that front? Anyway, a tool like this (if trustworthy) would go a long way to helping me in this area. Also I do like that its in bash and not compiled.

Was this made with LLMs?