Netresec is an independent software vendor with focus on the network security field. We specialize in software for network forensics and analysis of network traffic.
Our most well known product is NetworkMiner, which is available in a professional as well as free open source version. We also develop and maintain other software tools, such as CapLoader (for big pcap files) and RawCap (a lightweight sniffer).
We at Netresec additionally maintain a comprehensive list of publicly available pcap files.
NetworkMiner is a Network Forensic Analysis Tool (NFAT) for Windows. NetworkMiner can be used as a passive network sniffer/packet capturing tool in order to detect operating systems, sessions, hostnames, open ports etc. without putting any traffic on the network. NetworkMiner can also parse PCAP files for off-line analysis and to regenerate/reassemble transmitted files and certificates from PCAP files.
CapLoader is a Windows tool designed to handle large amounts of captured network traffic in the tcpdump/libpcap format (PCAP). CapLoader displays the contents of opened PCAP files as a list of TCP and UDP flows. Users can select the flows of interest and quickly filter out those packets from the loaded PCAP files. Sending the selected flows/packets to a packet analyzer tool like Wireshark or NetworkMiner is then just a mouse click away.
PolarProxy is a transparent SSL/TLS proxy created for incident responders and malware researchers. PolarProxy is primarily designed to intercept and decrypt TLS encrypted traffic from malware that is run in a controlled environment, such as a sandbox. PolarProxy decrypts and re-encrypts TLS traffic, while also saving the decrypted traffic in a PCAP file.
Additional software from Netresec can be found on our products page.
Discovered Artifacts in Decrypted HTTPS
We released a PCAP file earlier this year, which was recorded as part of a live TLS decryption demo at the CS3Sthlm conference. The demo setup used PolarProxy running on a Raspberry Pi in order to decrypt all HTTPS traffic and save it in a PCAP file as unencrypted HTTP. This capture file was later u[...]
Reverse Proxy and TLS Termination
PolarProxy is primarily a TLS forward proxy, but it can also be used as a TLS termination proxy or reverse TLS proxy to intercept and decrypt incoming TLS traffic, such as HTTPS or IMAPS, before it is forwarded to a server. The proxied traffic can be accessed in decrypted form as a PCAP formatted da[...]
A new version of RawCap has been released today. This portable little sniffer now supports writing PCAP data to stdout and named pipes as an alternative to saving the captured packets to disk. We have also changed the target .NET Framework version from 2.0 to 4.7.2, so that you can run RawCap on a m[...]
Sniffing Decrypted TLS Traffic with Security Onion
Wouldn't it be awesome to have a NIDS like Snort, Suricata or Zeek inspect HTTP requests leaving your network inside TLS encrypted HTTPS traffic? Yeah, we think so too! We have therefore created this guide on how to configure Security Onion to sniff decrypted TLS traffic with help of PolarProxy. Pol[...]
Sharing a PCAP with Decrypted HTTPS
Modern malware and botnet C2 protocols use TLS encryption in order to blend in with 'normal' web traffic, sometimes even using legitimate services like Twitter or Instagram. I did a live demo at the CS3Sthlm conference last year, titled 'TLS Interception and Decryption', where I showed how TLS inter[...]