Netresec naturbild

Network Forensics and
Network Security Monitoring

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 logo


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 logo


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 logo


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.


Headlines from our Network Security Blog:

Analysing a malware PCAP with IcedID and Cobalt Strike traffic
This network forensics walkthrough is based on two pcap files released by Brad Duncan on The traffic was generated by executing a malicious JS file called StolenImages_Evidence.js in a sandbox environment. The capture file starts with a DNS lookup for, whi[...]

Live Online Training - PCAP in the Morning
Would you like to spend four mornings in May analyzing capture files together with me? I have now scheduled a live online network forensics training called 'PCAP in the Morning' that will run on May 3-6 (Monday to Thursday) between 8:30 AM and 12:30 PM EDT (US Eastern Daylight Time). We will be anal[...]

Targeting Process for the SolarWinds Backdoor
The SolarWinds Orion backdoor, known as SUNBURST or Solorigate, has been analyzed by numerous experts from Microsoft, FireEye and several anti-virus vendors. However, we have noticed that many of the published reports are either lacking or incorrect in how they describe the steps involved when a cli[...]

Twenty-three SUNBURST Targets Identified
Remember when Igor Kuznetsov and Costin Raiu announced that two of the victims in FireEye's SUNBURST IOC list were ***net.***.com and central.***.gov on Kaspersky's Securelist blog in December? Reuters later reported that these victims were Cox Communications and Pima County. We can now reveal that[...]

Robust Indicators of Compromise for SUNBURST
There has been a great deal of confusion regarding what network based Indicators of Compromise (IOC) SolarWinds Orion customers can use to self assess whether or not they have been targeted after having installed a software update with the SUNBURST backdoor. Many of the published IOCs only indicate[...]

Finding Targeted SUNBURST Victims with pDNS
Our SunburstDomainDecoder tool can now be used to identify SUNBURST victims that have been explicitly targeted by the attackers. The only input needed is passive DNS (pDNS) data for subdomains. Companies and organizations that have installed trojanized a SolarWinds Orion update contai[...]

Extracting Security Products from SUNBURST DNS Beacons
The latest version of our SunburstDomainDecoder (v1.7) can be used to reveal which endpoint protection applications that are installed on trojanized SolarWinds Orion deployments. The security application info is extracted from DNS queries for '' subdomains, which is used by SUNBURST as[...]

Reassembling Victim Domain Fragments from SUNBURST DNS
We are releasing a free tool called SunburstDomainDecoder today, which is created in order to help CERT organizations identify victims of the trojanized SolarWinds software update, known as SUNBURST or Solorigate. SunburstDomainDecoder can be fed with DNS queries to in order to reveal[...]

Capturing Decrypted TLS Traffic with Arkime
The latest version of Arkime (The Sniffer Formerly Known As Moloch) can now be fed with a real-time stream of decrypted HTTPS traffic from PolarProxy. All that is needed to enable this feature is to include 'pcapReadMethod=pcap-over-ip-server' in Arkime's config.ini file and start PolarProxy with th[...]

PolarProxy 0.8.16 Released
We are happy to announce a new release of the TLS decryption tool PolarProxy. The new version has been updated to support features like client certificates and a PCAP-over-IP connector. Client Certificates PolarProxy now supports client-authenticated TLS handshakes for outgoing connections to suppor[...]