Rewterz Threat Alert – PowerBrace Malware Targets Financial Organizations

Severity

High

Analysis Summary

PowerBrace is a PowerShell remote access tool (RAT) or backdoor having the functionality to run commands, manipulate files, upload/download files from a C2 server, manipulate running processes, collect system information and manipulate the Windows registry. It communicates over TLS with a custom protocol using XOR encoding. Minor obfuscation occurs throughout the script, which makes it slightly more difficult to analyse. The script uses several light forms of obfuscation. Function names and variable names are replaced with non-descriptive names, and strings are stored as base64 encoded Unicode. The PowerBrace malware was also observed in attacks on financial institutions in Q1 2020. 

This malware collects various operating system information and sends it to the C2 server. The collected data includes: 

• Internal IP address 

• Computer name 

• Username 

• OS version 

• OS architecture 

• Proxy status 

• Proxy server 

• Script path 

• Last boot time 

• OS caption 

• OS language 

• OS country code 

• Primary C2 address and port 

• Secondary C2 address and port 

• 32/64 bit system 

Impact

• Information disclosure
• Data exfiltration

Indicators of Compromise

Domain Name

lawanstore[.]com

MD5

b093a18d8de93a39f8d2cdc0fda06265

SHA-256

cb47b8e49881c8aed31e5b0c354e7eb14532c3ff6da69705142370bdaa289ebb

SHA1

a224f9f42514e3b3d895eed316bd6cf1fb5faf7e

Remediation

Block the threat indicators at their respective controls.