The risk actors related to the Gootkit malware have made “notable adjustments” to their toolset, including new parts and obfuscations to their an infection chains.
Google-owned Mandiant is monitoring the exercise cluster underneath the moniker UNC2565, noting that the utilization of the malware is “unique to this group.”
Gootkit, additionally referred to as Gootloader, is unfold by means of compromised web sites that victims are tricked into visiting when looking for business-related paperwork like agreements and contracts by way of a way referred to as search engine marketing (web optimization) poisoning.
The purported paperwork take the type of ZIP archives that harbor the JavaScript malware, which, when launched, paves the way in which for extra payloads equivalent to Cobalt Strike Beacon, FONELAUNCH, and SNOWCONE.
FONELAUNCH is a .NET-based loader designed to load an encoded payload into reminiscence, and SNOWCONE is a downloader that is tasked with retrieving next-stage payloads, sometimes IcedID, by way of HTTP.
Whereas the overarching objectives of Gootkit have remained unchanged, the assault sequence in itself has acquired important updates, whereby the JavaScript file inside the ZIP archive is trojanized and comprises one other obfuscated JavaScript file that consequently proceeds to execute the malware.
The brand new variant, which was noticed by the risk intelligence agency in November 2022, is being tracked as GOOTLOADER.POWERSHELL. It is value noting that the revamped an infection chain was additionally documented by Pattern Micro earlier this month, detailing Gootkit assaults concentrating on the Australian healthcare sector.
What’s extra, the malware authors are stated to have taken three completely different approaches to obscure Gootkit, together with concealing the code inside altered variations of respectable JavaScript libraries equivalent to jQuery, Chroma.js, and Underscore.js, in an try to flee detection.
It is not simply Gootkit, as three completely different flavors of FONELAUNCH – FONELAUNCH.FAX, FONELAUNCH.PHONE, and FONELAUNCH.DIALTONE – have been put to make use of by UNC2565 since Could 2021 to execute DLLs, .NET binaries, and PE recordsdata, indicating that the malware arsenal is being repeatedly maintained and up to date.
“These adjustments are illustrative of UNC2565’s energetic improvement and development in capabilities,” Mandiant researchers Govand Sinjari and Andy Morales stated.
