CISA analyzed 15 files associated with China Chopper malware. The files are modified Offline Address Book (OAB) Virtual Directory (VD) configuration files for Microsoft Exchange servers. The files have been modified with a variant of the China Chopper webshell. The webshells allow an attacker to remotely access the server and execute arbitrary code on the system(s).referenced in this bulletin or otherwise.
CISA analyzed 4 files associated with HyperBro malware. The files creates a backdoor program that is capable of uploading and downloading files to and from the system. The RAT is also capable of logging keystrokes and executing commands on the system.
Earlier this year, we started hunting for possible new DeftTorero (aka Lebanese Cedar, Volatile Cedar) artifacts. This threat actor is believed to originate from the Middle East and was publicly disclosed to the cybersecurity community as early as 2015. Notably, no other intelligence was shared until 2021, which led us to speculate on a possible shift by the threat actor to more fileless/LOLBINS techniques, and the use of known/common offensive tools publicly available on the internet that allows them to blend in.
Earlier this year, Mandiant identified a novel malware ecosystem impacting VMware ESXi, Linux vCenter servers, and Windows virtual machines that enables a threat actor to take the following actions:
1) Maintain persistent administrative access to the hypervisor
2) Send commands to the hypervisor that will be routed to the guest VM for execution
3) Transfer files between the ESXi hypervisor and guest machines running beneath it
4) Tamper with logging services on the hypervisor
Yesterday, cybersecurity vendor GTSC Cyber Security dropped a blog saying they had detected exploitation of a new Microsoft Exchange zero…