RegAsm.exe
- File Path:
C:\WINDOWS\Microsoft.NET\Framework64\v4.0.30319\RegAsm.exe - Description: Microsoft .NET Assembly Registration Utility
- Comments: Flavor=Retail
Hashes
| Type | Hash |
|---|---|
| MD5 | 15D0F3ABFB5A3E38E83EA61A082EF934 |
| SHA1 | 9FF4A64E44EFDCD088DFE489466ED612FFF1EF55 |
| SHA256 | 1136010A4706295F80343FE364D90D5789288DEAD5AB0ED0E0981D29AD669BBC |
| SHA384 | 26D8D84ADE0755C8FDF6E3CCEAA525DD9F5033E5FE5ADA1A6D47EF530410D0190F4F5046C2D91E79CA6C535B18412F41 |
| SHA512 | B33AA91069382A2F57275FBAE3CD94BF477C13AB263EE07A94422DA9BC3D43513DF4016449D103953D87CA672BA9E5F83D854D17E9228E865F5C1753466EEA5B |
| SSDEEP | 768:D8XcJiMjm2ieHFYPyCsSuJbn8dBhF+iSMH6Iq8ASYDKcagxW6l:PYMaNyFYPYSAb8dBndH+lDKcaL6l |
| PESHA1 | 0450D0707FF7734EA1C66BABBF16810586D45E2F |
| PE256 | 2AF324A5DF399003923593F9FFCE376A4DBED4F44FF3AB93EDEEF2D022AC3843 |
Runtime Data
Usage (stdout):
Microsoft .NET Framework Assembly Registration Utility version 4.8.4161.0
for Microsoft .NET Framework version 4.8.4161.0
Copyright (C) Microsoft Corporation. All rights reserved.
Syntax: RegAsm AssemblyName [Options]
Options:
/unregister Unregister types
/tlb[:FileName] Export the assembly to the specified type library
and register it
/regfile[:FileName] Generate a reg file with the specified name
instead of registering the types. This option
cannot be used with the /u or /tlb options
/codebase Set the code base in the registry
/registered Only refer to already registered type libraries
/asmpath:Directory Look for assembly references here
/nologo Prevents RegAsm from displaying logo
/silent Silent mode. Prevents displaying of success messages
/verbose Displays extra information
/? or /help Display this usage message
Usage (stderr):
RegAsm : error RA0000 : Failed to load 'C:\WINDOWS\system32\help' because it is not a valid .NET assembly
Loaded Modules:
| Path |
|---|
| C:\WINDOWS\Microsoft.NET\Framework64\v4.0.30319\RegAsm.exe |
| C:\WINDOWS\System32\KERNEL32.dll |
| C:\WINDOWS\System32\KERNELBASE.dll |
| C:\WINDOWS\SYSTEM32\MSCOREE.DLL |
| C:\WINDOWS\SYSTEM32\ntdll.dll |
Signature
- Status: Signature verified.
- Serial:
33000002ED2C45E4C145CF48440000000002ED - Thumbprint:
312860D2047EB81F8F58C29FF19ECDB4C634CF6A - Issuer: CN=Microsoft Windows Production PCA 2011, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
- Subject: CN=Microsoft Windows, O=Microsoft Corporation, L=Redmond, S=Washington, C=US
File Metadata
- Original Filename: RegAsm.exe
- Product Name: Microsoft .NET Framework
- Company Name: Microsoft Corporation
- File Version: 4.8.4161.0 built by: NET48REL1
- Product Version: 4.8.4161.0
- Language: English (United States)
- Legal Copyright: Microsoft Corporation. All rights reserved.
- Machine Type: 64-bit
File Scan
- VirusTotal Detections: 0/73
- VirusTotal Link: https://www.virustotal.com/gui/file/1136010a4706295f80343fe364d90d5789288dead5ab0ed0e0981d29ad669bbc/detection
File Similarity (ssdeep match)
| File | Score |
|---|---|
| C:\Windows\Microsoft.NET\Framework\v4.0.30319\RegAsm.exe | 72 |
| C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\RegAsm.exe | 86 |
| C:\Windows\Microsoft.NET\Framework64\v4.0.30319\RegAsm.exe | 80 |
Possible Misuse
The following table contains possible examples of RegAsm.exe being misused. While RegAsm.exe is not inherently malicious, its legitimate functionality can be abused for malicious purposes.
| Source | Source File | Example | License |
|---|---|---|---|
| sigma | proc_creation_win_bad_opsec_sacrificial_processes.yml | - https://docs.microsoft.com/en-us/dotnet/framework/tools/regasm-exe-assembly-registration-tool |
DRL 1.0 |
| sigma | proc_creation_win_bad_opsec_sacrificial_processes.yml | Image\|endswith: '\regasm.exe' |
DRL 1.0 |
| sigma | proc_creation_win_bad_opsec_sacrificial_processes.yml | CommandLine\|endswith: '\regasm.exe' |
DRL 1.0 |
| sigma | proc_creation_win_possible_applocker_bypass.yml | - '\regasm.exe' |
DRL 1.0 |
| LOLBAS | Regasm.yml | Name: Regasm.exe |
|
| LOLBAS | Regasm.yml | - Command: regasm.exe AllTheThingsx64.dll |
|
| LOLBAS | Regasm.yml | - Command: regasm.exe /U AllTheThingsx64.dll |
|
| LOLBAS | Regasm.yml | - Path: C:\Windows\Microsoft.NET\Framework\v2.0.50727\regasm.exe |
|
| LOLBAS | Regasm.yml | - Path: C:\Windows\Microsoft.NET\Framework64\v2.0.50727\regasm.exe |
|
| LOLBAS | Regasm.yml | - Path: C:\Windows\Microsoft.NET\Framework\v4.0.30319\regasm.exe |
|
| LOLBAS | Regasm.yml | - Path: C:\Windows\Microsoft.NET\Framework64\v4.0.30319\regasm.exe |
|
| LOLBAS | Regasm.yml | - IOC: regasm.exe executing dll file |
|
| LOLBAS | Regasm.yml | - Link: https://pentestlab.blog/2017/05/19/applocker-bypass-regasm-and-regsvcs/ |
|
| LOLBAS | Regsvcs.yml | Description: Regsvcs and Regasm are Windows command-line utilities that are used to register .NET Component Object Model (COM) assemblies |
|
| LOLBAS | Regsvcs.yml | - Link: https://pentestlab.blog/2017/05/19/applocker-bypass-regasm-and-regsvcs/ |
|
| atomic-red-team | index.md | - T1218.009 Regsvcs/Regasm | MIT License. © 2018 Red Canary |
| atomic-red-team | index.md | - Atomic Test #1: Regasm Uninstall Method Call Test [windows] | MIT License. © 2018 Red Canary |
| atomic-red-team | windows-index.md | - T1218.009 Regsvcs/Regasm | MIT License. © 2018 Red Canary |
| atomic-red-team | windows-index.md | - Atomic Test #1: Regasm Uninstall Method Call Test [windows] | MIT License. © 2018 Red Canary |
| atomic-red-team | matrix.md | | | | | | Regsvcs/Regasm | | | | | | | | | MIT License. © 2018 Red Canary |
| atomic-red-team | windows-matrix.md | | | | | | Regsvcs/Regasm | | | | | | | | | MIT License. © 2018 Red Canary |
| atomic-red-team | T1218.009.md | # T1218.009 - Regsvcs/Regasm | MIT License. © 2018 Red Canary |
| atomic-red-team | T1218.009.md | <blockquote>Adversaries may abuse Regsvcs and Regasm to proxy execution of code through a trusted Windows utility. Regsvcs and Regasm are Windows command-line utilities that are used to register .NET Component Object Model (COM) assemblies. Both are digitally signed by Microsoft. (Citation: MSDN Regsvcs) (Citation: MSDN Regasm) | MIT License. © 2018 Red Canary |
| atomic-red-team | T1218.009.md | Both utilities may be used to bypass application control through use of attributes within the binary to specify code that should be run before registration or unregistration: [ComRegisterFunction] or [ComUnregisterFunction] respectively. The code with the registration and unregistration attributes will be executed even if the process is run under insufficient privileges and fails to execute. (Citation: LOLBAS Regsvcs)(Citation: LOLBAS Regasm)</blockquote> |
MIT License. © 2018 Red Canary |
| atomic-red-team | T1218.009.md | - Atomic Test #1 - Regasm Uninstall Method Call Test | MIT License. © 2018 Red Canary |
| atomic-red-team | T1218.009.md | ## Atomic Test #1 - Regasm Uninstall Method Call Test | MIT License. © 2018 Red Canary |
| atomic-red-team | T1218.009.md | C:\Windows\Microsoft.NET\Framework\v4.0.30319\regasm.exe /U #{output_file} | MIT License. © 2018 Red Canary |
| signature-base | apt_oilrig_oct17.yar | $s2 = “C:\Windows\Microsoft.NET\Framework\v2.0.50727\RegAsm.exe” fullword wide | CC BY-NC 4.0 |
MIT License. Copyright (c) 2020-2021 Strontic.