In a previous article, we introduced a piece of malware that ThreatSpike detected in December 2020, moving laterally between hosts. The attack consisted of two components: A text editor repurposed as a launcher for the actual payload, identified as Cobalt Strike’s Beacon.
The array of phishing vectors used by attackers is constantly expanding. On a daily basis we observe numerous different phishing themes such as voicemails, fake invoices and documents requiring signing. Recently, we have seen more topical themes such as US elections, COVID-19 and Brexit.
December 2020, the weeks before Christmas, saw an increase in reported malware activity that culminated most prominently in the Sunburst Trojan attacks - events that are still developing as of today. As we were asserting our readiness to respond to new threats under our watch, we identified a suspicious executable being copied to a remote network share.
In this blog we will explore several ways that Alternate Data Streams (ADS) are abused by attackers to hide files and evade detection, defences based on them (and ways to bypass those defences!) but also how they can be used to help malware evade dynamic analysis.
Visual Basic (VB) and its derivatives - VBA and VBScript - are common attack vectors when targeting Windows systems. These languages allow users and attackers alike to complete security-sensitive tasks such as accessing the internet, running command-line instructions and editing the Registry.
