Detecting DNS implants: Old kitten, new tricks – A Saitama Case Study

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 evade detection. As no … Continue reading Detecting DNS implants: Old kitten, new tricks – A Saitama Case Study →

Flubot: the evolution of a notorious Android Banking Malware

Authored by Alberto Segura (main author) and Rolf Govers (co-author) Summary Flubot is an Android based malware that has been distributed in the past 1.5 years inEurope, Asia and Oceania affecting thousands of devices of mostly unsuspecting victims.Like the majority of Android banking malware, Flubot abuses Accessibility Permissions and Servicesin order to steal the victim's … Continue reading Flubot: the evolution of a notorious Android Banking Malware →

Adventures in the land of BumbleBee

Authored by: Nikolaos Totosis, Nikolaos Pantazopoulos and Mike Stokkel Executive summary BUMBLEBEE is a new malicious loader that is being used by several threat actors and has been observed to download different malicious samples. The key points are: BUMBLEBEE is statically linked with the open-source libraries OpenSSL 1.1.0f, Boost (version 1.68). In addition, it is … Continue reading Adventures in the land of BumbleBee →

SharkBot: a “new” generation Android banking Trojan being distributed on Google Play Store

Authors: Alberto Segura, Malware analystRolf Govers, Malware analyst & Forensic IT Expert NCC Group, as well as many other researchers noticed a rise in Android malware last year, especillay Android banking malware. Within the Treat Intelligence team of NCC Group we’re looking closely to several of these malware families to provide valuable information to our … Continue reading SharkBot: a “new” generation Android banking Trojan being distributed on Google Play Store →

log4j-jndi-be-gone: A simple mitigation for CVE-2021-44228

tl;dr Run our new tool by adding -javaagent:log4j-jndi-be-gone-1.0.0-standalone.jar to all of your JVM Java stuff to stop log4j from loading classes remotely over LDAP. This will prevent malicious inputs from triggering the “Log4Shell” vulnerability and gaining remote code execution on your systems. In this post, we first offer some context on the vulnerability, the released fixes (and their shortcomings), and … Continue reading log4j-jndi-be-gone: A simple mitigation for CVE-2021-44228 →

Log4Shell: Reconnaissance and post exploitation network detection

Note: This blogpost will be live-updated with new information. NCC Group’s RIFT is intending to publish PCAPs of different exploitation methods in the near future – last updated December 14th at 13:00 UTC About the Research and Intelligence Fusion Team (RIFT): RIFT leverages our strategic analysis, data science, and threat hunting capabilities to create actionable threat … Continue reading Log4Shell: Reconnaissance and post exploitation network detection →

Encryption Does Not Equal Invisibility – Detecting Anomalous TLS Certificates with the Half-Space-Trees Algorithm

Author: Margit Hazenbroek 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 company that … Continue reading Encryption Does Not Equal Invisibility – Detecting Anomalous TLS Certificates with the Half-Space-Trees Algorithm →

Tracking a P2P network related to TA505

This post is by Nikolaos Pantazopoulos and Michael Sandee tl;dr – Executive Summary For the past few months NCC Group has been closely tracking the operations of TA505 and the development of their various projects (e.g. Clop). During this research we encountered a number of binary files that we have attributed to the developer(s) of … Continue reading Tracking a P2P network related to TA505 →

TA505 exploits SolarWinds Serv-U vulnerability (CVE-2021-35211) for initial access

NCC Group’s global Cyber Incident Response Team have observed an increase in Clop ransomware victims in the past weeks. The surge can be traced back to a vulnerability in SolarWinds Serv-U that is being abused by the TA505 threat actor. TA505 is a known cybercrime threat actor, who is known for extortion attacks using the … Continue reading TA505 exploits SolarWinds Serv-U vulnerability (CVE-2021-35211) for initial access →

Reverse engineering and decrypting CyberArk vault credential files

Author: Jelle Vergeer This blog will be a technical deep-dive into CyberArk credential files and how the credentials stored in these files are encrypted and decrypted. I discovered it was possible to reverse engineer the encryption and key generation algorithms and decrypt the encrypted vault password. I also provide a python implementation to decrypt the … Continue reading Reverse engineering and decrypting CyberArk vault credential files →