[Bumblebee](https://attack.mitre.org/software/S1039) is a custom loader written in C++ that has been used by multiple threat actors, including possible initial access brokers, to download and execute additional payloads since at least March 2022. [Bumblebee](https://attack.mitre.org/software/S1039) has been linked to ransomware operations including [Conti](https://attack.mitre.org/software/S0575), Quantum, and Mountlocker and derived its name from the appearance of "bumblebee" in the user-agent.(Citation: Google EXOTIC LILY March 2022)(Citation: Proofpoint Bumblebee April 2022)(Citation: Symantec Bumblebee June 2022)