Stephen Reese

SiLK Network Traffic Analysis Visualization with R and Rayon

In this post, the process for retroactively identifying and graphing a HTTPS DDoS of service condition is described. Why do we care about graphing, because it can be a great way to describe data to folks that may not be interested in looking at it in a tabular form, e …

Detecting Tor network traffic with YaF and Python

This entry continues a series of posts on identifying Tor network traffic and usage. The entry will demonstrate how to parse the output of YaF records via mediator using a Python script in order to determine if the SSL certificate values match the pattern of Tor certificates. It is assumed …

Detecting Tor network traffic with SiLK

This entry continues a series of posts on identifying Tor network traffic and usage. This post is not to argue the merits of allowing Tor to run on a network. However, the entry will demonstrate how to create a set of Tor server IP addresses to parse network flow using …

Variance in rwfilter results from netflow v5 and YaF

Looking over some netflow data I notice some variance between the two sensors. Sensor s0 is v5 netflow data from a Cisco switch, s1 is from a network tap listening between a Router on a Stick and said Cisco switch. The latter is a capture from YaF listening on a …


Configure SiLK on Linux for NetFlow collection from a Cisco router

This guide walks through configuring SiLK from a source install on a Debian 6 host in order to collect NetFlow data from a Cisco router. The guides here and here written by CERT NetSA are quite good but lack some detail specific to the Debian distribution which required a bit …