A couple years ago I set up a simple brochure-ware site for the School Board in the district here in Brooklyn, hosted on a VPS instance on Linode, to publicize the dates of public meetings, meeting minutes, etc. The VPS doesn't contain any sensitive information so I locked down the ports to 80, 443, and 22, hardened the SSH with measures like fail2ban, kept the system updated every week or so, and called it a day.
Last week, though, the site was compromised. Blowing the instance away and re-creating it from physical backups is not a problem, but in poring through the system to figure out how it was breached I realized both that my own security chops aren't deep enough and that standard best security practices might not be good enough anymore, anyway, given the many vulnerabilities exposed in the last year and realities like the NSA trove that Shadow Brokers leaked.
So the question for the more experienced security professionals in the Soylent community is, can they recommend a good guide and/or site to hone linux security chops and forensic skills that's current?
(Score: 2) by Phoenix666 on Saturday June 03 2017, @11:00PM (1 child)
Yeah the site didn't require PHP, so I didn't use it. There's no interactivity on the site. It's all simple HTML/CSS.
I didn't change the default ports for the HTTP/S or SSH because it doesn't do much.
I did set up a mail server, but used the Perfect Mail Server for Debian on HowtoForge and kept the packages updated.
Fail2ban is set up, and the funny thing is it's there still bouncing everything from China the way it's supposed to. But still there are reverse SSH connections to that same IP range that are being spawned by a process on the system I haven't found yet.
Nuking the instance and recreating it from backups is trivial, and no sensitive data was lost or compromised, but I rather want to use the occasion to deepen my knowledge of the subject matter area of security since it's been a bit of a wake-up call.
Do you have any recommendations for more advanced (or, hell, even intermediate-to-advanced) sources to help me on the way there?
Washington DC delenda est.
(Score: 0) by Anonymous Coward on Sunday June 04 2017, @02:48AM
maybe it has to do with how fail2ban handles the blocklist? maybe fail2ban is the "hacker"?