Gootkit, also known as GootLoader, has been seen used in targeted attacks against healthcare and financial organizations in the US, UK, and Australia, according to a recent report from Cybereason. Gootkit was first discovered in 2014 as a banking Trojan, but since 2021 has acted as a malware loader instead.
The Gootkit infection starts with SEO poisoning and malicious Google ads, tricking a user into thinking they are visiting a piece of software’s legitimate website when in reality they are visiting a malicious one. Once the Gootkit payload has been executed, malicious JavaScript is executed that establishes persistence on the device and launches the main loader malware. This JavaScript is notable because the malicious code is hidden within legitimate JavaScript libraries such as jQuery, Chroma.js, and Underscore.js. Once the malware has been executed, Gootkit was seen loading both Cobalt Strike and SystemBC to allow the threat actor to escalate privileges and laterally move within the infected network.
These attacks are notable in how aggressive the threat actors were in attempting to compromise the entire network. Additional network compromise and privilege escalation were achieved in less than four hours from the original Gootkit infection, leading to a very quick compromise of the entire environment.