Fox-IT

Authored by Joshua Kamp Executive summary The authors behind Android banking malware Vultur have been spotted adding new technical features, which allow the malware operator to further remotely interact with the victim’s mobile device. Vultur has also started masquerading more of its malicious activity by encrypting its C2 communication, using…

Author: Axel Boesenach and Erik Schamper In this blog post we will go into a user-friendly memory scanning Python library that was created out of the necessity of having more control during memory scanning. We will give an overview of how this library works, share the thought process and the…

At Fox-IT (part of NCC Group) identifying servers that host nefarious activities is a critical aspect of our threat intelligence. One approach involves looking for anomalies in responses of HTTP servers. Sometimes cybercriminals that host malicious servers employ tactics that involve mimicking the responses of legitimate software to evade detection.…

Mathew Vermeer is a doctoral candidate at the Organisation Governance department of the faculty of Technology, Policy and Management of Delft University of Technology. At the same university, he has received both a BSc degree in Computer Science and Engineering, as well as a MSc degree in Computer Science with…

Fox-IT (part of NCC Group) has uncovered a large-scale exploitation campaign of Citrix NetScalers in a joint effort with the Dutch Institute of Vulnerability Disclosure (DIVD). An adversary appears to have exploited CVE-2023-3519 in an automated fashion, placing webshells on vulnerable NetScalers to gain persistent access. The adversary can execute…

Max Groot Ruud van Luijk TL;DR A recently uncovered malware sample dubbed ‘Saitama’ was uncovered by security firm Malwarebytes in a weaponized document, possibly targeted towards the Jordan government. This Saitama implant uses DNS as its sole Command and Control channel and utilizes long sleep times and (sub)domain randomization to…

Since we published about identifying Cobalt Strike Team Servers in the wild just over three years ago, we’ve collected over 128,000 beacons from over 24,000 active Team Servers. Today, RIFT is making this extensive beacon dataset publicly available in combination with the open-source release of dissect.cobaltstrike, our Python library for…

tl;dr An approach to detecting suspicious TLS certificates using an incremental anomaly detection model is discussed. This model utilizes the Half-Space-Trees algorithm and provides our security operations teams (SOC) with the opportunity to detect suspicious behavior, in real-time, even when network traffic is encrypted.  The prevalence of encrypted traffic As a…

Over the past few months NCC Group has observed an increasing number of data breach extortion cases, where the attacker steals data and threatens to publish said data online if the victim decides not to pay. Given the current threat landscape, most notable is the absence of ransomware or any…

tl:dr Incremental Learning is an extremely useful machine learning paradigm for deriving insight into cyber security datasets. This post provides a simple example involving JA3 hashes showing how some of the foundational algorithms that enable incremental learning techniques can be applied to novelty detection (the first time something has happened)…

by fumik0_ the RIFT TL:DR Our Research and Intelligence Fusion Team have been tracking the Gozi variant RM3 for close to 30 months. In this post we provide some history, analysis and observations on this most pernicious family of banking malware targeting Oceania, the UK, Germany and Italy.  We’ll start with an overview of its origins and current operations before…

Threat Intel Analyst: Antonis Terefos (@Tera0017)Data Scientist: Anne Postma (@A_Postma) 1. Introduction TA505 is a sophisticated and innovative threat actor, with plenty of cybercrime experience, that engages in targeted attacks across multiple sectors and geographies for financial gain. Over time, TA505 evolved from a lesser partner to a mature, self-subsisting…

Author: Jelle Vergeer Introduction A while ago we had a forensics case in which a Linux server was compromised and a modified OpenSSH binary was loaded into the memory of a webserver. The modified OpenSSH binary was used as a backdoor to the system for the attackers. The customer had…

This month, members of NCC Group will be presenting their work at the following conferences: Dirk-Jan Mollema, “Walking Your Dog in Multiple Forests: Breaking AD Trust Boundaries through Kerberos Vulnerabilities,” to be presented at Black Hat Asia 2020 (Virtual – October 1 2020) Sanne Maasakkers, “Improve Security Awareness Campaigns by…

Author: Jelle Vergeer The first part of this blog will be the story of how this tool found it’s way into existence, the problems we faced and the thought process followed. The second part will be a more technical deep dive into the tool itself, how to use it, and…

Detecting both ‘offensive’ and obfuscated PowerShell scripts in Splunk using Windows Event Log 4104 This blog provides a ‘look behind the scenes’ at the RIFT Data Science team and describes the process of moving from the need or an idea for research towards models that can be used in practice.…

Authors: Nikolaos Pantazopoulos, Stefano Antenucci (@Antelox), Michael Sandee and in close collaboration with NCC’s RIFT. About the Research and Intelligence Fusion Team (RIFT):RIFT leverages our strategic analysis, data science, and threat hunting capabilities to create actionable threat intelligence, ranging from IOCs and detection capabilities to strategic reports on tomorrow’s threat…

Publicly discovered in late April 2020, the Team9 malware family (also known as ‘Bazar’) appears to be a new malware being developed by the group behind Trickbot. Even though the development of the malware appears to be recent, the developers have already developed two components with rich functionality. The purpose…