Subj : Re: Protection
To : Sam Penwright
From : Chris Hizny
Date : Wed Feb 02 2022 09:11 am
SP> What are you using to protect your computer and bbs
SP> like peerblock firewall, pfsense- with like a check point hardware or
SP> any other hardware? I receive a lot of hits from Russia, Korean
SP> Republic, China etc. So I thought I would see what everyone is
Well, for what it's worth, before I put up my board I was interested in what exactly these were, so using Netcat and a shell script, I made a kind of honeypot which prints a login and password prompt, logs those, then prints a fake shell prompt ($ or # depending on the attempted login).
Nearly all hits to telnet ports are bots/worms spraying-and-praying across the net, looking for -- so far as I can tell -- cheapo security cameras and other IoT devices with known default logins and passwords. (I could determine this by watching what login/password combinations were being tried, then searching for devices with known defaults of these combinations)
Most are webcams - for some reason - with brand names they don't sell in my country - as to your comment, most are from places like China and Russia.
Once they are "logged in," nearly all of them attempt to run busybox with a payload. Some attempt to wget the payload from an external site although for some reason those have mostly faded away. The busybox command line assumes the payload is already baked into busybox (i.e. the device already has a compromised busybox executable).
The scripts are rather dumb; they don't check for result text or error text from the commands they run.
The larger point here is that unless you're running a system with common default logins and passwords, these present no threat to your system. They are nuisances.
Moving your system off of the default ports completely stops them, since these scripts are looking for low-hanging fruit and targets of opportunity. This isn't really security-through-obscurity so much as it is moving out of the way of an indiscriminately fired machine gun.
fail2ban and similar techniques are fine as far as they go but there are so many of these coming from so many different IP addresses, it's whack-a-mole. Maybe since it is automated, no big deal.
There's no real threat here. Not that better security is a bad thing; have at it, but I figured I'd post this just to provide some additional information.
Of the ports I watch (basically everything in /etc/services), these are the most common hits (note the most hammered port -- hence the issue SysOps have to put up with):
None of the ports you see in this list are open/provide services on the servers I monitor, so no one should be legitimately hitting them.
The other traffic you see are from research/scanning IPs - shodan.io is one, which are people mapping the net or searching for vulnerabilities - generally good guys (like Arbor Observatory).
Anyway slightly off-topic to your question but I hope there's something interesting in here of interest to someone.
