Medium
Emerging during the pandemic, a new threat group is targeting Taiwanese users with COVID-19 themed phishing campaigns. The use of COVID-19 themes as a lure has been a consistent tactic in their campaigns since their appearance. The most recent campaign indicates a clear intent to victimize users in Taiwan based on the content and language. The email claims that the attachment contains information regarding making an appointment for testing at the Taiwan CDC. The researchers note the email was high quality and indicated sophisticated targeting, unlike most phishing emails which contain grammatical mistakes or appear to be fake. Attached is an ISO containing a packed .NET executable identified as RoboSki. RoboSki, upon execution, runs a DLL file in memory that extracts shell code from an embedded PNG image. The shell code, in turn, drops the next payload in memory, the ReZer0 malware. This kicks off a chain of payload executions in memory leading to the final payload, which in this campaign is the Nanocore RAT.