Government entities, military organizations, and civilian users in Ukraine and Poland have been targeted as part of a series of campaigns designed to steal sensitive data and gain persistent remote access to the infected systems.
The intrusion set, which stretches from April 2022 to July 2023, leverages phishing lures and decoy documents to deploy a downloader malware called PicassoLoader, which acts as a conduit to launch Cobalt Strike Beacon and njRAT.
"The attacks used a multistage infection chain initiated with malicious Microsoft Office documents, most commonly using Microsoft Excel and PowerPoint file formats," Cisco Talos researcher Vanja Svajcer
said in a new report. "This was followed by an executable downloader and payload concealed in an image file, likely to make its detection more difficult."