For nearly four years and perhaps even longer, Forest Blizzard (aka Fancy Bear, aka APT28) has been using a custom tool that exploits a specific vulnerability in Windows Print Spooler service (CVE-2022-38028). Dubbed GooseEgg, the tool is a launcher application that can spawn other applications with SYSTEM-level permissions, thus helping the hackers to perform remote code execution, install backdoors, steal credentials, and more.

Source: Help Net Security