MITRE ATT&CK - Técnica

T1546.011: Application Shimming

Application Shimming (T1546.011) é uma técnica catalogada no MITRE ATT&CK Enterprise usada como referência para mapear comportamento adversário em auditorias de segurança.

Técnica T1546.011 Enterprise ATT&CK

Contexto para AppSec

Em uma auditoria de AppSec, Application Shimming deve ser usada para revisar caminhos em que código, configuração, dependências ou infraestrutura podem viabilizar o comportamento descrito pela MITRE. No ATT&CK, ela aparece em Privilege Escalation e Persistence. As plataformas mapeadas pela MITRE incluem Windows. No Vigly, esse contexto ajuda a conectar evidências do repositório com priorização e remediação.

Tática/fase Privilege Escalation, Persistence
Plataformas MITRE Windows

Descrição oficial original do MITRE ATT&CK

Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by application shims. The Microsoft Windows Application Compatibility Infrastructure/Framework (Application Shim) was created to allow for backward compatibility of software as the operating system codebase changes over time. For example, the application shimming feature allows developers to apply fixes to applications (without rewriting code) that were created for Windows XP so that it will work with Windows 10. Within the framework, shims are created to act as a buffer between the program (or more specifically, the Import Address Table) and the Windows OS. When a program is executed, the shim cache is referenced to determine if the program requires the use of the shim database (.sdb). If so, the shim database uses hooking to redirect the code as necessary in order to communicate with the OS. A list of all shims currently installed by the default Windows installer (sdbinst.exe) is kept in: * %WINDIR%\AppPatch\sysmain.sdb and

  • hklm\software\microsoft\windows nt\currentversion\appcompatflags\installedsdb Custom databases are stored in: * %WINDIR%\AppPatch\custom & %WINDIR%\AppPatch\AppPatch64\Custom and
  • hklm\software\microsoft\windows nt\currentversion\appcompatflags\custom To keep shims secure, Windows designed them to run in user mode so they cannot modify the kernel and you must have administrator privileges to install a shim. However, certain shims can be used to Bypass User Account Control (UAC and RedirectEXE), inject DLLs into processes (InjectDLL), disable Data Execution Prevention (DisableNX) and Structure Exception Handling (DisableSEH), and intercept memory addresses (GetProcAddress). Utilizing these shims may allow an adversary to perform several malicious acts such as elevate privileges, install backdoors, disable defenses like Windows Defender, etc. Shims can also be abused to establish persistence by continuously being invoked by affected programs.
Ver fonte oficial no MITRE ATT&CK

Como o Vigly audita a técnica Application Shimming automaticamente na sua pipeline

O Vigly cruza sinais de SAST, modelagem de ameaças, regras de negócio e evidências do repositório para priorizar riscos reais antes que eles cheguem à produção.

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