17_APT41Campaign.txt

On March 5, 2020, researcher Steven Seeley, published an advisory and released proof-of-concept code for a zero-day remote code execution vulnerability in Zoho ManageEngine Desktop Central versions prior to 10.0.474 (CVE-2020-10189). Beginning on March 8, FireEye observed APT41 use 91.208.184[.]78 to attempt to exploit the Zoho ManageEngine vulnerability at more than a dozen FireEye customers, which resulted in the compromise of at least five separate customers. FireEye observed two separate variations of how the payloads (install.bat and storesyncsvc.dll) were deployed. In the first variation the CVE-2020-10189 exploit was used to directly upload “logger.zip”, a simple Java based program, which contained a set of commands to use PowerShell to download and execute install.bat and storesyncsvc.dll. FireEye observed APT41 leverage the Microsoft BITS Admin command-line tool to download install.bat (MD5: 7966c2c546b71e800397a67f942858d0) from known APT41 infrastructure 66.42.98[.]220 on port 12345.In both variations, the install.bat batch file was used to install persistence for a trial-version of Cobalt Strike BEACON loader named storesyncsvc.dll (MD5: 5909983db4d9023e4098e56361c96a6f). Storesyncsvc.dll was a Cobalt Strike BEACON implant (trial-version) which connected to exchange.dumb1[.]com (with a DNS resolution of 74.82.201[.]8) using a jquery malleable command and control (C2) profile. Within a few hours of initial exploitation, APT41 used the storescyncsvc.dll BEACON backdoor to download a secondary backdoor with a different C2 address that uses Microsoft CertUtil, a common TTP that we’ve observed APT41 use in past intrusions, which they then used to download 2.exe (MD5: 3e856162c36b532925c8226b4ed3481c). The file 2.exe was a VMProtected Meterpreter downloader used to download Cobalt Strike BEACON shellcode. The downloaded BEACON shellcode connected to the same C2 server: 91.208.184[.]78. We believe this is an example of the actor attempting to diversify post-exploitation access to the compromised systems.