Security researchers from McAfee uncovered the global campaign that targets nuclear, defense, energy, and financial companies.
Threat actors sends emails disguising as a job recruiter with a weaponized macro included Word document that runs a shellcode to inject Sharpshooter downloader into the memory of Word.
The injected downloader will download two files Second-stage payload dubbed Rising Sun and Second OLE (Word) document. The payload downloaded to the startup folder to ensure persistance of the system.
Whereas the OLE document downloaded to %LOCALAPPDATA% and it is used to lure the malicious content.
The Rising Sun implant is a fully functional modular backdoor that performs reconnaissance on the victim’s network. It collects the following information from the machine such as Network adapter Computer name, username, IP address information, Native system information and OS product name.
The configuration data encrypted with RC4 algorithm and the implact decodes it to establish connection with the control server.
After the initial reconnaissance the implant carries out Data encryption and exfiltration. Once it gathers the required data it encrypts with RC4 algorithm.
It also performs an additional layer of obfuscation by Base64-encoding the RC4 encrypted data.
The implant contains 14 backdoor capabilities
- Execute commands
- Get drive information
- Launch process from Windows binary
- Get processes information
- Terminate process
- Read file
- Get file times
- Clear process memory
- Write file to disk
- Delete file
- Get additional file information for files in a directory
- Connect to an IP address
- Change file attributes
- Variant of change file attributes
Between October and November 2018, the Rising Sun appeared in 87 organizations around the world and predominantly in the United States, according to McAfee telemetry analysis.
Our discovery of this new, high-function implant is another example of how targeted attacks attempt to gain intelligence. The malware moves in several steps. We will continue to monitor this campaign to share their insights, attribution and who is responsible for Operation Sharpshooter.