Anatomy of an insider breach originating from a contractor's laptop

Keith Siepel, IT Manager at Hydrotech, Inc. (Guest Contributor) | Tuesday March 26, 2019

The following guest-authored blog post examines an advanced cyber-threat discovered by Darktrace on a customer’s network.


On the morning of Thursday, February 14, 2019 at 7:51 a.m. EST, a contract instructor turned on their computer as they had every morning that week to prepare for their upcoming class. They connected their laptop to our WiFi network, just as they had each morning, and proceeded to check email.

Unfortunately, this morning was a little different, as while they were checking email, their computer was checking other things on our network:

18 seconds later...

Our Darktrace system notified us via email of a potential problem and by marking the device in yellow on their Threat Visualizer.

Notice that the time lapse from the initial scanning process until the offending system is marked as a problem is approximately 15 seconds.

Subsequently the Darktrace system upgraded the threat status to “red” and notified us a second time of a network scan in progress. Darktrace also marked the offending device with a dark red/orange color to indicate the severity of the threat. Note the time in the bottom left corner is exactly 11 seconds after the first warning.

By 7:53 a.m., the instructor’s laptop had attempted connections to every device on the network and prompted the following image on the Darktrace Threat Visualizer interface, leaving no doubt that there was a problem with the instructor’s laptop.

The offending laptop was removed from our network. We weren’t going to wait to see how long it might take for our other, signature-based systems to identify and remediate this problem.

Working with the instructor, I scanned the laptop with various tools in an attempt to identify and remove the malware that created this network scan. Unfortunately, we were not able to find malware running on this device using traditional tools.  Subsequently, we determined that the source of this breach probably originated from a USB drive that was shared with the contract instructor by one of his students the night before.

Just as Darktrace detected a zero-day trojan on our network in January, I was able to identify and remove a threat from our network using Darktrace before I spent days, weeks, or even months waiting for our antivirus/malware signatures to hopefully identify it.

About the authors

Justin Fier

Justin Fier is the Director for Cyber Intelligence & Analytics at Darktrace, based in Washington D.C. Justin is one of the US’s leading cyber intelligence experts, and his insights have been widely reported in leading media outlets, including Wall Street Journal, CNN, the Washington Post, and VICELAND. With over 10 years of experience in cyber defense, Justin has supported various elements in the US intelligence community, holding mission-critical security roles with Lockheed Martin, Northrop Grumman Mission Systems and Abraxas. Justin is also a highly-skilled technical specialist, and works with Darktrace’s strategic global customers on threat analysis, defensive cyber operations, protecting IoT, and machine learning.

Dave Palmer

Dave Palmer is the Director of Technology at Darktrace, overseeing the mathematics and engineering teams and project strategies. With over ten years of experience at the forefront of government intelligence operations, Palmer has worked across UK intelligence agencies GCHQ & MI5, where he delivered mission-critical infrastructure services, including the replacement and security of entire global networks, the development of operational internet capabilities and the management of critical disaster recovery incidents. He holds a first-class degree in Computer Science and Software Engineering from the University of Birmingham.

Andrew Tsonchev

Andrew advises Darktrace’s strategic Fortune 500 customers on advanced threat detection, machine learning and autonomous response. He has a technical background in threat analysis and research, and holds a first-class degree in physics from Oxford University and a first-class degree in philosophy from King’s College London. He was most recently featured on BBC World, BBC Morning and Al Jazeera to comment on the news regarding the GRU.

Max Heinemeyer

Max is a cyber security expert with over eight years’ experience in the field specializing in network monitoring and offensive security. At Darktrace, Max works with strategic customers to help them investigate and respond to threats as well as overseeing the cyber security analyst team in the Cambridge UK headquarters. Prior to his current role, Max led the Threat and Vulnerability Management department for Hewlett-Packard in Central Europe. He was a member of the German Chaos Computer Club, working as a white hat hacker in penetration testing and red teaming engagements. Max holds a MSc from the University of Duisburg-Essen and a BSc from the Cooperative State University Stuttgart in International Business Information Systems.