BBTok Targeting Brazil: Deobfuscating the .NET Loader with dnlib and PowerShell
Essential information
- Published
- 26/09/2024 12:55
- Modified
- 27/09/2024 17:47
- Tags
- 2024-09-26 bbtok
- Related entities
- 1 intrusion sets (apt), 19 techniques (mitre), 1 malware, 1 others
Description
This analysis dissects the infection chain of BBTok, a Brazilian-targeted threat. The malware utilizes an ISO image containing a shortcut file and various components. It employs the Microsoft Build Engine to compile and execute malicious C# code on the victim's machine. The core component, Trammy.dll, is obfuscated using ConfuserEx and utilizes AppDomain Manager Injection for execution. The malware creates a log file, gathers system information, and establishes persistence through scheduled tasks and service creation. It downloads additional components, including CCProxy for traffic manipulation, and a Delphi payload. The attack specifically targets Brazilian IP addresses and employs evasion techniques to avoid detection.