Medium
Over the past year, the Astaroth infostealer trojan has evolved into one of today’s stealthiest malware strains, containing a slew of anti-analysis and anti-sandbox checks to prevent security researchers from detecting and analyzing its operations. Different types of lures, including COVID-19, are being used to trick victims into installing Astaroth, an information stealing malware package. The variation of Astaroth being deployed includes complex obfuscation, anti-analysis, and evasion techniques to avoid detection and analysis. Another feature of this variation of Astaroth is its use of encoded/encrypted YouTube channel descriptions for communication with its command and control servers. The infection vector in this campaign is emails written in Portuguese targeting Brazilian users at the moment. The email uses a number of different lures to entice the user into clicking the URL embedded in the body. Once clicked, the victim is taken to an attacker owned server where the initial payload is a ZIP file is downloaded from a Google-based server.