Bumblebee malware has resurfaced in the cybercriminal threat landscape [4], targeting multiple US-based organizations in a recent campaign observed in February 2024, according to Proofpoint research [1] [2] [4]. This sophisticated downloader [3] [4], first discovered in March 2022 [3], has been utilized by various threat groups as an initial access broker to download and execute additional payloads.


The recent campaign involving Bumblebee consisted of over 2,000 emails, marking its return after a four-month absence from Proofpoint researchers’ threat data. This surge in cybercriminal activity coincides with the reappearance of several notorious threat actors following a temporary “Winter lull.” The emails, sent from the sender “info@quarlesaa[. [4]]com” with the subject “Voicemail February,” contained OneDrive URLs leading to a Word document that spoofed the consumer electronics company Humane.

Unlike previous infiltrations [1] [2], this new campaign employed a different attack chain. Bumblebee has been distributed through various methods, including trojanizing popular software tools [1]. Capable of downloading and executing shellcode [3], as well as the Cobalt Strike and Sliver tools [3], Bumblebee has proven to be a versatile and dangerous threat.

Proofpoint’s research has identified a total of 230 campaigns involving Bumblebee from March 2022 to October 2023, highlighting the extent of its impact and prevalence in the threat landscape.


The resurgence of Bumblebee malware poses significant risks to organizations, as it serves as a gateway for threat actors to gain initial access and execute malicious payloads. The use of different attack chains and the ability to trojanize popular software tools further complicates detection and mitigation efforts.

To combat this threat, organizations should remain vigilant and implement robust cybersecurity measures. Regularly updating security software, educating employees about phishing techniques, and monitoring network traffic for suspicious activity are crucial steps in mitigating the risks associated with Bumblebee and similar malware.

As cybercriminals continue to evolve their tactics, it is imperative for organizations to stay informed about emerging threats and adapt their security strategies accordingly. By doing so, they can better protect their networks, data [3], and reputation from the ever-present danger of malware attacks.


[1] https://www.infosecurity-magazine.com/news/bumblebee-malware-new-attack/
[2] https://ciso2ciso.com/notorious-bumblebee-malware-re-emerges-with-new-attack-methods-source-www-infosecurity-magazine-com/
[3] https://duo.com/decipher/u-s-organizations-targeted-in-bumblebee-malware-campaign
[4] https://www.proofpoint.com/us/blog/threat-insight/bumblebee-buzzes-back-black