It is now apparent to the information security community that intrusions starting with BazarLoader frequently end with Conti ransomware.
This case saw such a conclusion.
There are some evident similarities in cases that involve Conti ransomware.
Ransomware operators’ tooling and overall tasks performed tend to match across the cluster.
When we look at our earlier Conti case, this becomes noticeable.
This could be due to the widely circulated Conti manual that was leaked by an affiliate.
In this case, we saw the same pattern of events with tools like net, nltest, ShareFinder for discovery, Cobalt Strike for C2, and WMIC remote process creation for expanding their access within the network.
Even though the intrusion lasted for five days total, Cobalt Strike and hands-on keyboard operators showed up in the first two hours of the intrusion.
Straight away, they started gathering information to get the lay of the land using Net commands.
Then they continued looking for open shares by executing the PowerView module, Invoke-ShareFinder.
After collecting and dissecting the results from ShareFinder, they appeared to have a good understanding of the server and workstation layout of the organization as they started executing commands to gather information from specific, high-value servers.
During that time, we saw errors when operators failed to alter specific parameters that indicate the operator is acting from a pre-defined playbook.
They eventually decided to pivot laterally to a server using WMIC to execute a DLL Cobalt Strike beacon.
Once they had access to the remote server via the Cobalt Strike beacon, they re-ran Invoke-ShareFinder and then exfiltrated data of interest from a different server using the Rclone application via the MEGA cloud storage service.
On the second day, the threat actors used RDP to access the backup server and in doing so, reviewed the backup settings, and running processes on the server via the taskmanager GUI.
On day four, the threat actors returned and ran another round of exfiltration using Rclone and MEGA again.
On the fifth day, they moved fast towards their final objective, which was Conti ransomware.
Before executing Conti, they used RDP to install and configure the AnyDesk remote desktop application.
Having GUI access, they attempted to use ProcessHacker to dump the LSASS process. After this last step, they deployed Conti ransomware via a batch script to all domain joined systems.