# SANS ISC: InfoSec Handlers Diary Blog - SANS Internet Storm Center InfoSec Handlers Diary Blog **isc.sans.edu/diary/rss/28664** ## Bumblebee Malware from TransferXL URLs **Published: 2022-05-19** **Last Updated: 2022-05-20 04:48:30 UTC** **[by Brad Duncan (Version: 1)](https://isc.sans.edu/handler_list.html#brad-duncan)** [2 comment(s)](https://isc.sans.edu/forums/diary/Bumblebee+Malware+from+TransferXL+URLs/28664/#comments) **_Introduction_** Last month, Google's Threat Analysis Group (TAG) reported on EXOTIC LILY using file transfer services like TransferNow, TransferXL, WeTransfer, or OneDrive to distribute [malware (link). Threat researchers like @k3dg3 occasionally report malware samples from](https://blog.google/threat-analysis-group/exposing-initial-access-broker-ties-conti/) [this activity. Based on @k3dg3's recent tweet, I searched through VirusTotal and found a](https://twitter.com/k3dg3/status/1526252566803271680) handful of active TransferXL URLs delivering ISO files for Bumblebee malware. Today's diary reviews an infection generated from this activity on Wednesday 2022-05-18. _Shown above: Flow chart for infection discussed in this diary._ **_TransferXL URLs_** TransferXL is a legitimate file sharing service. However, like other services with a cost-free tier, TransferXL has been abused by criminals as a way to distribute malicious files. However, with TransferXL, we have the benefit of seeing an email address used to share the malicious file. The image below shows a malicious TransferXL URL recently submitted to VirusTotal. Viewed in a web browser, it sends a malicious file. The associated email address is jhurris@wolsleyindustrialgroup.com. ----- _Shown above: Malicious TransferXL URL delivering malware._ The downloaded zip archive contains an ISO disk image. When double-clicked, this file is mounted as a DVD drive. The ISO file contains a visible Windows shortcut and a hidden malware DLL for Bumblebee. Double-clicking the Windows shortcut will run the hidden malware DLL on a vulnerable Windows host. ----- _Shown above: Downloaded ISO file mounted as a disk image containing Windows shortcut_ _and hidden malware DLL._ **_Traffic from an infection_** After downloading malware from the malicious TransferXL URL, the infected host generated Bumblebee C2 traffic to 194.135.33[.]144 over TCP port 443. ----- _Shown above: Initial infection activity with Bumblebee C2 traffic filtered in Wireshark._ Approximately 15 minutes after the Bumblebee C2 traffic first appeared, the infected Windows host generated HTTPS traffic to ec2-3-144-143-232-us-east**_2.compute.amazonaws[.]com on 3.144.143[.]242 over TCP port 443. The infected_** host sent approximately 5.5 MB of data out and received approximately 4.0 MB of data back from that server. ----- _Shown above: Encrypted (HTTPS) traffic to an amazonAWS server._ Approximately 14 minutes after HTTPS traffic to the amazonAWS server, HTTPS Cobalt Strike traffic appeared on 23.106.215[.]123 over TCP port 443 using xenilik[.]com as the domain. It lasted approximately 3 minutes. ----- _Shown above: Traffic from the infection showing Cobalt Strike activity._ **_Indicators of Compromise (IOCs)_** TransferXL URLs associated with the above email returning zip archives containing malicious ISO files. **_hxxps://www.transferxl[.]com/download/00ZNPDZqZwZ9m_** **_hxxps://www.transferxl[.]com/download/00jwbtRXtsSsZX_** **_hxxps://www.transferxl[.]com/download/00vJV4K6QVXSq6_** **_hxxps://www.transferxl[.]com/download/00y12VGg75h7K_** **_hxxps://www.transferxl[.]com/download/08j8ZRjHFkVxxc_** NOTE: The above URLs usually have ?utm_source=downloadmail&utm_medium=e-mail appended to them. Email addresses associated with malicious TransferXL URLs: **_andresbolivar@southerncompanygas[.]co_** **_jhurris@wolsleyindustrialgroup[.]com_** **_m.jones@wolsleyindustrialgroup[.]com_** **_mjones@wolsleyindustrialgroup[.]co_** Domains from the above emails: **_southerncompanygas[.]co - registered 2022-04-27_** **_wolsleyindustrialgroup[.]com - registered 2022-04-29_** **_wolsleyindustrialgroup[.]co - not registered_** Malware from an infected Windows host: SHA256 hash: [1ec8c7e21090fb4c667f40c8720388a89789c569169fe0e41ec81567df499aac](https://www.virustotal.com/gui/file/1ec8c7e21090fb4c667f40c8720388a89789c569169fe0e41ec81567df499aac) File size: 669,897 bytes File name: TransferXL-00jdMwft3vVZ7Q.zip File description: Zip archive retrieved from TransferXL URL SHA256 hash: [24aa82e1a085412686af5d178810fc0d056c5b8167ae5b88973b33071aa14569](https://www.virustotal.com/gui/file/24aa82e1a085412686af5d178810fc0d056c5b8167ae5b88973b33071aa14569) File size: 1,052,672 bytes File name: documents-2205210.iso File description: ISO file extracted from downloaded zip archive SHA256 hash: [ade875616534b755f33f6012ea263da808dd7eb50bc903fc97722f37fac7c164](https://www.virustotal.com/gui/file/ade875616534b755f33f6012ea263da808dd7eb50bc903fc97722f37fac7c164) File size: 1 191 bytes ----- File name: New Folder.lnk File description: Windows shortcut contained in ISO file Shortcut: C:\Windows\System32\rundll32.exe spc.dll,JQhnMKwhpA SHA256 hash: [88c07354f1d7b0485452d5c39dc1a6d73884e163bc5489c40adc6662602b4d76](https://www.virustotal.com/gui/file/88c07354f1d7b0485452d5c39dc1a6d73884e163bc5489c40adc6662602b4d76) File size: 997,888 bytes File name: spc.dll File description: 64-bit DLL (hidden flag set) for Bumblebee malware Run method: rundll32.exe [filename],JQhnMKwhpA Traffic from the infected Windows host: 194.135.33[.]144 port 443 - Bumblebee C2 HTTPS traffic 3.144.143[.]242 port 443 - ec2-3-144-143-242.us-east**_2.compute.amazonaws[.]com - HTTPS traffic_** 23.106.215[.]123 port 443 - xenilik[.]com - Cobalt Strike HTTPS traffic **_Final words_** [As the Google TAG blog post notes, EXOTIC LILY is using this method to push Bumblebee](https://blog.google/threat-analysis-group/exposing-initial-access-broker-ties-conti/) malware, and Bumblebee leads to further malware like Cobalt Strike. And Cobalt Strike has been documented by different sources as leading to ransomware. Today's diary reviewed a Bumblebee malware infection associated with EXOTIC LILY that led to Cobalt Strike activity. [Pcap and malware samples associated with this infection are available here.](https://www.malware-traffic-analysis.net/2022/05/18/index2.html) --Brad Duncan brad [at] malware-traffic-analysis.net [Keywords: Bumblebee malware EXOTIC LILY TransferXL Cobalt Strike](https://isc.sans.edu/tag.html?tag=Bumblebee) [2 comment(s)](https://isc.sans.edu/forums/diary/Bumblebee+Malware+from+TransferXL+URLs/28664/) [Join us at SANS! Attend with Brad Duncan in starting](http://10.10.0.46/data-production/pdf_1653510684_06914c.html) -----