Network Forensics training at x33fcon

I will teach Network Forensics for Incident Response at the IT security conference x33fcon in Gdynia, Poland on June 11-12. In this hands-on class you will get a chance to perform network based threat hunting and deep dive into packet analysis for two days. The first day will be spent using open source tools, such as Wireshark, NetworkMiner, Suricata, Zeek, tcpflow and ngrep. On the second day we’ll also use NetworkMiner Professional and CapLoader. All training participants will get a 6 month license for CapLoader as well as NetworkMiner Professional.

About x33fcon

x33fcon is held in Gdynia (Gdańsk), which is located on the Baltic coast in northern Poland. The conference’s focus is on collaboration between attackers and defenders. Their goal is to encourage security professionals to consider both perspectives while working more closely together.

More information about this two-day training can be found at x33fcon’s website as well as on Netresec’s training page.

Posted by Erik Hjelmvik on Monday, 18 March 2024 10:25:00 (UTC/GMT)

Tags: #Netresec​ #Training​ #Class​ #Network Forensics​

Network Forensics Training - Spring 2024

I will teach two live online network forensics classes in March, one on European morning time, and the other on US morning time. The subject for both classes is network forensics in an incident response context.

The training is split into four interactive morning sessions, so that you have the afternoon free to either practice what you learned in class or catch up with your “normal” day job. The number of attendees will be limited in order to provide a good environment for taking questions. A maximum of 15 attendees will be accepted per class. The registration will be closed once we reach this attendee limit.

• 🇪🇺 March 4-7, 2024: PCAP in the Morning Europe
  ⏲️ Time: 8:30 AM to 12:30 PM CET
  💸 Price: € 930 EUR per student
• 🇺🇸 March 25-28, 2023: PCAP in the Morning US
  ⏲️ Time: 9:30 AM to 1:30 PM EDT
  💸 Price: $1,000 USD per student

We will be analyzing a unique 30GB PCAP data set captured during June 2020 on an Internet connected network with multiple clients, an AD server, a web server, an android tablet and some embedded devices. As you’ve probably guessed, the capture files contain traffic from multiple intrusions by various attackers, including APT style attackers and botnet operators. The initial attack vectors are using techniques like exploitation of web vulnerabilities, spear phishing, a supply chain attack and a man-on-the-side attack! In this training you'll get first-hand experience looking at C2 and backdoor protocols, such as Cobalt Strike, TrickBot, njRAT and Meterpreter.

See our training page for more info about the “PCAP in the Morning” classes.

To sign up for a class, simply send an email to sales@netresec.com with the class dates, your name and invoice address. We will then send you a PayPal payment link that you can use to complete your training registration.

Hope to see you there!

Cheers,
Erik Hjelmvik
Creator of NetworkMiner and founder of Netresec

Posted by Erik Hjelmvik on Monday, 11 December 2023 12:55:00 (UTC/GMT)

Tags: #Netresec​ #PCAP​ #Training​ #Network Forensics​ #Class​

Online Network Forensics Class

I will be teaching two live online network forensics classes this spring, one in March and one in April. The March class is adapted to American time and the April one is adapted to European time. Both classes focus on doing network forensics in an incident response context.

The training is split into four interactive morning sessions, so that you have the afternoon free to either practice what you learned in class or do your “normal” day job. The number of attendees will be limited in order to enable attendees to ask questions or even cover short ad-hoc side tracks. We plan to accept 10 to 15 attendees per class. The class registration will be closed once we reach this attendee limit.

• 🇺🇸 March 20-23, 2023: PCAP in the Morning US
  ⏲️ Time: 9:30 AM to 1:30 PM EDT
  💸 Price: $1,000 USD per student
• 🇪🇺 April 17-20, 2023: PCAP in the Morning Europe
  ⏲️ Time: 8:30 AM to 12:30 PM CEST
  💸 Price: € 950 EUR per student

We will be analyzing a unique 30GB PCAP data set captured during June 2020 on an Internet connected network with multiple clients, an AD server, a web server, an android tablet and some embedded devices. As you’ve probably guessed, the capture files contain traffic from multiple intrusions by various attackers, including APT style attackers and botnet operators. The initial attack vectors are using techniques like exploitation of web vulnerabilities, spear phishing, a supply chain attack and a man-on-the-side attack!

See our training page for more info about the “PCAP in the Morning” classes.

To sign up for a class, simply send an email to sales@netresec.com with the class dates, your name and invoice address. We will then send you a PayPal payment link that you can use to complete your training registration.

Hope to see you there!

Cheers,
Erik Hjelmvik
Creator of NetworkMiner and founder of Netresec

Posted by Erik Hjelmvik on Tuesday, 17 January 2023 10:18:00 (UTC/GMT)

Tags: #Netresec​ #PCAP​ #Training​ #Network Forensics​ #Class​

Network Forensics Classes for EU and US

We have now scheduled two new live online classes, one in September and one in October. The September class is adapted to European time and the October one is adapted to American time. The contents are exactly the same in both classes.

The training is split into four interactive morning sessions (4 hours each), so that you have the afternoon free to either practice what you learned in class or do your “normal” day job. The number of attendees will be limited in order to enable attendees to ask questions or even cover short ad-hoc side tracks. We plan to accept something like 10 to 15 attendees per class. The class registration will be closed once we reach this attendee limit.

• 🇪🇺 September 20-23, 2021. Live Online Training "PCAP in the Morning EU"
  ⏲️ Time: 8:30 AM to 12:30 PM CET (Central European Time)
  💸 Price: € 820 EUR per student (€ 738 EUR if registering before August 20)
• 🇺🇸 October 25-28, 2021. Live Online Training "PCAP in the Morning US"
  ⏲️ Time: 9:00 AM to 1:00 PM EDT (US Eastern Daylight Time)
  💸 Price: $1,000 USD per student ($900 USD if registering before September 25)

We will be analyzing a unique 30GB PCAP data set captured during June 2020 on an Internet connected network with multiple clients, an AD server, a web server, an android tablet and some embedded devices. As you’ve probably guessed, the capture files contain traffic from multiple intrusions by various attackers, including APT style attackers and botnet operators. The initial attack vectors are using techniques like exploitation of web vulnerabilities, spear phishing, a supply chain attack and a man-on-the-side attack!

See our training page for more info about the “PCAP in the Morning” classes.

To sign up for a class, simply send an email to sales@netresec.com with the class dates, your name and invoice address. We will then send you a PayPal payment link that you can use to complete your training registration.

Hope to see you there!

Cheers,
Erik Hjelmvik
Creator of NetworkMiner and founder of Netresec

Posted by Erik Hjelmvik on Monday, 07 June 2021 09:55:00 (UTC/GMT)

Tags: #Netresec​ #PCAP​ #Training​ #Network Forensics​ #Class​

Detecting Cobalt Strike and Hancitor traffic in PCAP

This video shows how Cobalt Strike and Hancitor C2 traffic can be detected using CapLoader.

I bet you’re going:

😱 OMG he’s analyzing Windows malware on a Windows PC!!!

Relax, I know what I’m doing. I have also taken the precaution of analyzing the PCAP file in a Windows Sandbox, which just takes a couple of seconds to deploy and run.

The capture file I’m looking at is called “2021-05-13-Hancitor-traffic-with-Ficker-Stealer-and-Cobalt-Strike.pcap” and can be downloaded from here: https://malware-traffic-analysis.net/2021/05/13/index.html

CapLoader’s Services tab shows us that the connections to TCP 80 and 443 on 103.207.42.11 are very periodic, with a detected period of exactly 1 minute. CapLoader successfully identifies the protocols for these two services as Cobalt Strike over HTTP and Cobalt Strike over SSL, respectively. The third service in this list is also very periodic, that’s the Hancitor trojan beaconing to its C2 server every two minutes.

CapLoader uses machine learning to identify the application layer protocol based on the behavior of the traffic, not the port number. This means that there can be false positives, i.e. the protocol classification that CapLoader gives a flow or service might be wrong. It is more common, however, for CapLoader to yield false negatives, which means that it can't identify the protocol. The detection of Cobalt Strike inside of HTTP and SSL traffic was recently introduced in the latest 1.9 release of CapLoader. I expected this feature to detect Cobalt Strike traffic in HTTP, but I was delighted to see that CapLoader often detects even TLS encrypted Cobalt Strike beaconing with really good precision!

As shown in the video, the Cobalt Strike beacon config can easily be extracted from the network traffic using NetworkMiner and Didier Stevens’ 1768 K python script.

The output from Didier’s 7868.py tool looks something like this:

As you can see, it uses HTTP for transport with a “sleeptime” of 1 minute (60000 ms) and 0% jitter. This means that a new connection will be made to the Cobalt Strike C2 server every minute. The fact that there was no jitter is what gives this service such a high value in CapLoader’s “Periodicity” column.

Network Forensics Training

Are you interested in learning more about how to analyze network traffic from Cobalt Strike and other backdoors, malware and hacker tools? Then take a look at the live online network forensics classes I will be teaching in September and October!

Posted by Erik Hjelmvik on Monday, 31 May 2021 08:30:00 (UTC/GMT)

Tags: #Netresec​ #Cobalt Strike​ #CobaltStrike​ #periodicity​ #Protocol Identification​ #PIPI​ #CapLoader​ #1768.py​ #Windows Sandbox​ #PCAP​ #NSM​ #video​ #videotutorial​

CapLoader 1.9 Released

A new version of the PCAP filtering tool CapLoader has been released today. The new CapLoader version 1.9 is now even better at identifying protocols and periodic beacons than before. The user interface has also been improved to make it easier to filter and drill down in network traffic to extract interesting, malicious or unusual traffic.

More Protocols Identified

We’ve added port-independent protocol detection for over 20 new protocols since the last release. The newly added protocols include some that are used by malicious tools and backdoors such as hTran, RevengeRAT, Tofsee and Winsecsrv, as well as legitimate protocols like WireGuard (VPN) and RemoteFX (UDP based remote desktop). We’ve also improved our support for ICS traffic analysis by adding protocol identification of SCADA protocols DNP3 and IEC 60870-5-104.

CapLoader also detects what we call “sub-protocols”, which are communication protocols that use other L7 protocols as transport. We have extended the sub-protocol detection in CapLoader 1.9 to include traffic like Anchor_DNS and dnscat traffic, which both run on top of DNS. We have also added detection of Cobalt Strike beacons over HTTP and HTTPS, even though the latter is quite difficult to detect due to the application data being encrypted.

Improved Usability

CapLoader 1.9 comes with several user interface improvements that help you solve the “needle in the haystack” problem even more efficiently than before.

The context menus in the Flows, Services and Hosts tabs can now be used to select rows based on values in any column, such as “Select all flows where Duration > 10 minutes” (when right-clicking a 10 minute flow).

The “Keyword Filter” is now called “Row Filter” in order to avoid getting it mixed up with the “Find Keyword” feature. The Row Filter has also been enhanced with a new filtering mode, to complement the Contains / All Words / Any Words / RegEx options, which is called “Column Criteria”. The Column Criteria can be used to filter the displayed rows based on the values in a user-specified column. The Column Criteria “Duration > 00:10:00” will, for example, only show flows that are 10 minutes or longer, while “ASN = 3301” shows the flows going to Telia’s AS3301.

Image: CapLoader with Row Filter Column Criteria "Duration > 00:10:00"

We have also extended CapLoader's BPF implementation to support VLAN id’s, so that you can use expressions like “vlan 100” as input filter as well as display filter. The BPF implementation also supports logic operators, so that more advanced filters like “(tcp port 80 or port 443) and not net 149.154.172.0/22” can be used.

CapLoader has a method for detecting periodic connection patterns, which was introduced in CapLoader 1.4. This feature can be used to detect clients that connect to a service at regular intervals, such as a beacon used for command-and-control or email client connecting to a mail server. We have improved the periodicity detection in CapLoader 1.9 so that it now detects periodic services more accurately.

The Initial Round Trip Time (iRRT) in the Flows and Services tabs is now measured in milliseconds instead of seconds in order to avoid “bulky numbers” (h/t Eddi).

There was previously a significant delay when selecting many flows at once (like 100.000). We’ve improved the performance of this feature in CapLoader 1.9, so that you can now select several hundred thousands flows at once without having to wait for an unresponsive GUI to update.

More OSINT Lookup Services

A feature in CapLoader that often comes in handy is the ability to right-click a flow, service or host and open a website with OSINT information about the clicked IP address or domain name. We have now replaced some of the OSINT services with new better ones.

The new services we’ve added to CapLoader 1.9 for performing online OSINT lookups of IP addresses, network services and domain names are:

• CIRCL BGP Ranking
• Hacker Target Reverse Lookup
• IPAddress.com
• OpenDNS
• RIPEstat
• RiskIQ
• Scamalytics
• Spur
• Spyse
• ThreatFox
• URLhaus
• ZoomEye

Bug fixes and Credits

Several bugs have been fixed in this new release of CapLoader, much thanks to feedback we’ve received from our users. We’d like to thank Anders Regert and Mandy van Oosterhout for reporting bugs in CapLoaders “Save As” feature. We’d also like to thank Hyun Dowon for reporting a snap length corruption bug that previously appeared when exporting flows from Pcap-NG files We have also fixed an issue where capture files were previously not always merged in chronological order when being aggregated.

Updating to the Latest Release

Users who have purchased a license for CapLoader can download a free update to version 1.9 from our customer portal. All others can download a free 30 day trial from the CapLoader product page (no registration required).

Posted by Erik Hjelmvik on Tuesday, 25 May 2021 12:20:00 (UTC/GMT)

Tags: #Netresec​ #CapLoader​ #PCAP​ #Pcap-NG​ #IEC-104​ #CobaltStrike​ #BPF​ #periodicity​ #OSINT​

Running NetworkMiner in Windows Sandbox

NetworkMiner can be run in a highly efficient Windows Sandbox in order to analyze malicious PCAP files in Windows without accidentally infecting your Windows PC. This blog post shows how to set up a Windows Sandbox that always boots up a fresh install of Windows 10 with the latest version of NetworkMiner installed.

I generally recommend analyzing Windows malware in Linux, or some other non-Windows environment, in order to avoid accidentally infecting yourself (NetworkMiner runs fine in Linux btw). Nevertheless, I still often find myself loading capture files containing malicious network traffic into CapLoader and NetworkMiner under Windows. I have previously demonstrated that this can be a quick and crude way to perform an anti virus scan of files contained in a pcap file.

Windows Sandbox

If you want to analyze malicious traffic in Windows with minimal risk of infecting yourself then you should definitely check out Microsoft’s Windows Sandbox (available in Windows 10 Pro and Enterprise editions). The Windows Sandbox is using Windows containers, so it’s very efficient compared to spinning up a full Windows VM. It also provides features like kernel isolation, so that the sandbox container doesn’t use the same kernel as the host, and ensures that a new Windows environment is created every time the sandbox is run. Windows Sandbox also doesn't run any anti-virus, so it won't interfere with the extraction of malicious contents from within the analyzed capture files.

Follow these steps to install Windows Sandbox:

1. Run OptionalFeatures.exe, aka “Turn Windows features on or off”
2. Enable the “Windows Sandbox” feature (check the box)
3. Reboot

Or run this PowerShell command as administrator and then reboot:

Then create a sandbox config, which downloads and installs the latest version of NetworkMiner every time the sandbox is started, by creating a file called “NetworkMinerSandbox.wsb” with the following contents:

Note: Replace “C:\Users\Erik\pcap” with whatever location your capture files are at

After starting NetworkMinerSandbox.wsb you’ll have a fresh Windows machine up and running within a couple of seconds. The latest version of NetworkMiner and your PCAP dir are both accessible from the sandbox’s desktop.

Image: NetworkMiner 2.6 installed in a clean Windows Sandbox environment

Moving files in or out of the sandbox is just a matter of copy and paste (Ctrl+C / Ctrl+V).

VirtualBox and Windows Sandbox

Are you using VirtualBox to run virtual machines on your Windows host and getting an error message saying “Failed to open a session for the virtual machine”, with details such as “Cannot enable nested VT-x/AMD-V without nested-paging and unrestricted guest execution” or “Failed to get device handle and/or partition ID”, after enabling Windows Sandbox?

Even though Windows Sandbox doesn’t need Hyper-V it still requires a hypervisor, which unfortunately conflicts with VirtualBox. You can disable the hypervisor by running the following command as administrator:

...and then rebooting the computer before starting a VirtualBox VM with “nested VT-x” enabled. Turning off the hypervisor will unfortunately prevent Windows Sandbox from running, giving an error message saying “No hypervisor was found. Please enable hypervisor support.” (Error 0xc0351000)

To re-enable the hypervisor, in order to run Windows Sandbox again, you’ll need to run

and reboot the host.

Update May 26, 2021

We have now uploaded a simple Windows Sandbox config to our website here:

https://www.netresec.com/?download=NetworkMinerSandbox

This script runs on any Windows Pro machine that has the Sandbox feature active.

Posted by Erik Hjelmvik on Tuesday, 11 May 2021 13:39:00 (UTC/GMT)

Tags: #Netresec​ #NetworkMiner​ #PCAP​ #Windows​ #Sandbox​ #Windows Sandbox​ #Malware​

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 analyzing a unique 30GB PCAP data set captured during June 2020 on an Internet connected network with multiple clients, an AD server, a web server, an android tablet and some embedded devices. As you’ve probably guessed, the capture files contain traffic from multiple intrusions by various attackers, including APT style attackers and botnet operators. The initial attack vectors are using techniques like exploitation of web vulnerabilities, spear phishing, a supply chain attack and a man-on-the-side attack!

See our training page for more info about the “PCAP in the Morning” training.

To sign up for my “PCAP in the Morning” class, simply send an email to sales@netresec.com with your name and invoice address. We will then send you a PayPal payment link that you can use to complete your training registration. The training costs $950 USD per participant, for which you will also get a six month single user license for NetworkMiner Professional and CapLoader.

Hope to see you there!

Cheers,
Erik Hjelmvik
Creator of NetworkMiner and founder of Netresec

Update June 7, 2021

We have now scheduled two new training events adapted for students in different time zones.

• September 20-23, 2021. Live Online Training "PCAP in the Morning EU" (🇪🇺)
• October 25-28, 2021. Live Online Training "PCAP in the Morning US" (🇺🇸)

More information about the network forensics classes can be found on our training page.

Posted by Erik Hjelmvik on Friday, 19 March 2021 14:03:00 (UTC/GMT)

Tags: #Netresec​ #PCAP​ #Training​ #Network Forensics​