LOLBAS/yml/OtherMSBinaries/Coregen.yml
2022-09-10 22:16:47 -04:00

49 lines
2.2 KiB
YAML

---
Name: coregen.exe
Description: Binary coregen.exe (Microsoft CoreCLR Native Image Generator) loads exported function GetCLRRuntimeHost from coreclr.dll or from .DLL in arbitrary path. Coregen is located within "C:\Program Files (x86)\Microsoft Silverlight\5.1.50918.0\" or another version of Silverlight. Coregen is signed by Microsoft and bundled with Microsoft Silverlight.
Author: Martin Sohn Christensen
Created: 2020-10-09
Commands:
- Command: coregen.exe /L C:\folder\evil.dll dummy_assembly_name
Description: Loads the target .DLL in arbitrary path specified with /L.
Usecase: Execute DLL code
Category: Execute
Privileges: User
MitreID: T1055
OperatingSystem: Windows
- Command: coregen.exe dummy_assembly_name
Description: Loads the coreclr.dll in the corgen.exe directory (e.g. C:\Program Files\Microsoft Silverlight\5.1.50918.0).
Usecase: Execute DLL code
Category: Execute
Privileges: User
MitreID: T1055
OperatingSystem: Windows
- Command: coregen.exe /L C:\folder\evil.dll dummy_assembly_name
Description: Loads the target .DLL in arbitrary path specified with /L. Since binary is signed it can also be used to bypass application whitelisting solutions.
Usecase: Execute DLL code
Category: AWL Bypass
Privileges: User
MitreID: T1218
OperatingSystem: Windows
Full_Path:
- Path: C:\Program Files\Microsoft Silverlight\5.1.50918.0\coregen.exe
- Path: C:\Program Files (x86)\Microsoft Silverlight\5.1.50918.0\coregen.exe
Code_Sample:
- Code:
Detection:
- IOC: coregen.exe loading .dll file not in "C:\Program Files (x86)\Microsoft Silverlight\5.1.50918.0\"
- IOC: coregen.exe loading .dll file not named coreclr.dll
- IOC: coregen.exe command line containing -L or -l
- IOC: coregen.exe command line containing unexpected/invald assembly name
- IOC: coregen.exe application crash by invalid assembly name
Resources:
- Link: https://www.youtube.com/watch?v=75XImxOOInU
- Link: https://www.fireeye.com/blog/threat-research/2019/10/staying-hidden-on-the-endpoint-evading-detection-with-shellcode.html
Acknowledgement:
- Person: Nicky Tyrer
Handle:
- Person: Evan Pena
Handle:
- Person: Casey Erikson
Handle: