Description

On January 26, 2023, Mandiant, an American cybersecurity company owned by Google, published a report to reveal new improvements made to Gootkit malware, such as adding new components and obfuscation techniques to their infection chains by its associated threat actor named UNC2565. As per reports, the threat actor UNC2565 has used the technique 'search engine optimization' (SEO) poisoning to compromise the websites to target victims when they search for business-related documents like agreements and contracts. Through these compromised websites, ZIP archives with JavaScript malware are distributed, which can further launch additional payloads like Cobalt Strike Beacon, FONELAUNCH, and SNOWCONE. This SNOWCONE is designed to download next-stage payloads like IcedID via HTTP, while FONELAUNCH is a .NET-based loader designed for loading an encoded payload into memory where threat actors used three different variants of FONELAUNCH like 'FONELAUNCH.FAX', 'FONELAUNCH.PHONE', and 'FONELAUNCH.DIALTONE' for executing the DLLs, .NET binaries, and PE files. Further, the threat actor's goals of Gootkit had remained the same but made significant changes to the attack sequence as the JavaScript file present in the ZIP archive is trojanized and contains another obfuscated JavaScript file that consequently executes the malware. To avoid detection, threat actors added three more approaches for obscuring Gootkit malware by concealing the code within altered versions of legitimate JavaScript libraries like 'jQuery', 'Chroma.js', and 'Underscore.js'. Additionally, Mandiant said threat actor UNC2565 is continuously updating and maintaining its malware collections. Mandiant found this new variant in November 2022, tracking it as 'GOOTLOADER.POWERSHELL', which is used to attack the Australian healthcare sector in January 2023.