Posts Tagged ‘comp’

The inherent risks of visualizing firewall probes

For some time now, I’ve been graphing all unsolicited network traffic destined for my network. For instance, it’s quite useful for detecting slow scans, which will show up as the diagonally aligned green scatter points in this plot (click to enlarge). Other scans and probes often happen faster, when the attacker isn’t much concerned about […]

SSH outbound connections – what are they trying?

Still fascinated by the outbound connection attempts from my Cowrie honeypot, I’ve been looking into what the intruders are trying to obtain with the outbound connections. As previously mentioned, there are bots actively attempting outbound connections towards a lot of remote services. Most are simply TCP socket connection attempts, but now and again the connection […]

Threat intelligence: OTX, Bro, SiLK, BIND RPZ, OSSEC

Building a toolbox around threat intelligence can be done with freely available tools. Shared information about malicious behaviour allows you to detect and sometimes prevent activity from – and to – Internet resources that could compromise your systems’ security. I’ve already described how to use lists of malicious domain names in a BIND RPZ (Response […]

ClamAV client/server setup

Note: This may very well be well-known information, but I found it difficult to get exact answers from the official ClamAV documentation, available man pages, and other kinds of documentation. The most useful hint originated from a mailing list thread considering ClamAV version 0.70, which is getting rather outdated. My original issue was getting antivirus […]

Visualizing honeypot activity

Certain honeypot intruders are quite persistently trying to open outbound SSH tunnels, as described in an earlier article. So far I’ve seen a lot of attempts to open tunnels towards mail server TCP ports 25 (SMTP), 465 (SMTPS) and 587 (submission); web servers on TCP ports 80 (HTTP) and 443 (HTTPS); but also several other […]

Honeynet outbound probes

My Cowrie honeypot is now seeing a surge of outbound SSH tunnel probes, both towards different mail servers but also towards a specific web server, probably with the purpose of informing about a successful intrusion. The honeypot has seen outbound attempts before, but not as persistent as with this bot from .ru. Cowrie fakes successful […]

More Logstalgia fun: Honeypot visualization

As the saying goes, when all you have is a hammer, everything looks like a nail. Well, it’s not that bad, but with a tool like Logstalgia available there’s a pretty low threshold for looking for other ways to use it. So why not try visualizing honeypot login activity? I’ve been running a honeypot for […]

Live visualizing Mikrotik firewall traffic with Logstalgia

Previously I’ve written about visualizing firewall activity. Revitalizing a fireplot graphing tool gives a nice day-to-day overview, but after being reminded of Logstalgia in this Imgur post I wanted to give live visualization a shot. Logstalgia is a neat tool for visualizing activity, by feeding it log files or live feeds. It’s originally designed for […]

Logging WordPress activity to OSSEC

Today I came across this blog article, explaining how to make WordPress log suspicious activity to an audit log file, which in turn can be monitored by OSSEC. Everything mentioned in the article was all fine and dandy, until I read the last paragraph: “Note that for this feature to work, you have to use […]

Munin and “Can’t use an undefined value as an ARRAY reference”

I recently came across a rather obscure and vague error in Munin: Can’t use an undefined value as an ARRAY reference at /usr/share/perl5/Munin/Master/   It seems there are quite a few error reports on this, with very different suggestions on how to solve the problem – and for some, the problem was never solved. In […]