Exploring the Depths of SolarMarker's Multi-tiered Infrastructure

SolarMarker (aka Yellow Cockatoo/Jupyter Infostealer) is an evolving multi-tiered information‑stealing malware active since 2020/2021 that targets education, healthcare, government, hospitality, and small-to-medium enterprises. The operator maintains separate clusters for active operations and testing, and uses evasion techniques such as Authenticode-signed payloads and large ZIP archives to bypass detection; defenders are advised to use application allow-lists (or training where not possible), maintain YARA and Snort rules, monitor network artifacts, and track the cybercriminal ecosystem.