Daserf — This backdoor has the functionality of a remote shell and can be used to execute commands, upload and download data, capture screenshots, and log keystrokes. xxmm (also known as Minzen) — This RAT and likely successor to Daserf AES-encrypts HTTP communications using a one-time encryption key. As of this publication, BRONZE BUTLER demonstrates a preference for concurrently using Datper and xxmm in its operations. CTU researchers identified an xxmm builder for xxmm (see Figure 2), which suggests that the threat actors customize the xxmm malware settings based on the target. Source: Secureworks) - RarStar — This custom tool uploads RAR archives to a specified URL as POST data (see Figure 6). RarStar encodes the POST data using Base64 and a custom XOR algorithm. Windows Credential Editor (WCE) — This tool obtains passwords from memory. T-SMB Scan — This SMB scanning tool was originally published on a Chinese program-sharing website (pudn.com). BRONZE BUTLER removed its help message functionality. WinRAR — This tool extracts tools for lateral movement and compresses data for exfiltration. When exfiltration is complete, the uploader (or Datper or xxmm) immediately uses the del command to delete the RAR archives. Search proxy log files for evidence of web server scanning using the URL patterns associated with BRONZE BUTLER activity