RegAsm.exe
- File Path:
C:\Windows\Microsoft.NET\Framework\v4.0.30319\RegAsm.exe - Description: Microsoft .NET Assembly Registration Utility
- Comments: Flavor=Retail
Hashes
| Type | Hash |
|---|---|
| MD5 | 0D5DF43AF2916F47D00C1573797C1A13 |
| SHA1 | 230AB5559E806574D26B4C20847C368ED55483B0 |
| SHA256 | C066AEE7AA3AA83F763EBC5541DAA266ED6C648FBFFCDE0D836A13B221BB2ADC |
| SHA384 | 3B4D3715DC2C5CC65579F673250BB355D5B9590ECAB1BE1E2F845090E5482CEC6C05D9DD7167B39FEA785B1850EFA498 |
| SHA512 | F96CF9E1890746B12DAF839A6D0F16F062B72C1B8A40439F96583F242980F10F867720232A6FA0F7D4D7AC0A7A6143981A5A130D6417EA98B181447134C7CFE2 |
| SSDEEP | 768:X8XcJiMjm2ieHlPyCsSuJbn8dBhFwlSMF6Iq8KSYDKbQ22qWqO8w1R:rYMaNylPYSAb8dBnsHsPDKbQBqTY |
| IMP | F34D5F2D4577ED6D9CEEC516C1F5A744 |
| PESHA1 | 045ADCAA09C5A7BE1AB28595CDEF3EB76103573A |
| PE256 | 1D9DF24BC73C37A5CD72E6E4090260B968EBD50C4A74035C02851F46A118B515 |
Runtime Data
Usage (stdout):
Microsoft .NET Framework Assembly Registration Utility version 4.8.4084.0
for Microsoft .NET Framework version 4.8.4084.0
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:\Users\user\help' because it is not a valid .NET assembly
Loaded Modules:
| Path |
|---|
| C:\Windows\Microsoft.NET\Framework\v4.0.30319\RegAsm.exe |
| C:\Windows\SYSTEM32\ntdll.dll |
| C:\Windows\System32\wow64.dll |
| C:\Windows\System32\wow64cpu.dll |
| C:\Windows\System32\wow64win.dll |
Signature
- Status: Signature verified.
- Serial:
330000023241FB59996DCC4DFF000000000232 - Thumbprint:
FF82BC38E1DA5E596DF374C53E3617F7EDA36B06 - 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: 4.8.4084.0 built by: NET48REL1
- Product Version: 4.8.4084.0
- Language: English (United States)
- Legal Copyright: Microsoft Corporation. All rights reserved.
- Machine Type: 32-bit
File Scan
- VirusTotal Detections: 0/73
- VirusTotal Link: https://www.virustotal.com/gui/file/c066aee7aa3aa83f763ebc5541daa266ed6c648fbffcde0d836a13b221bb2adc/detection
File Similarity (ssdeep match)
| File | Score |
|---|---|
| C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\RegAsm.exe | 77 |
| C:\WINDOWS\Microsoft.NET\Framework64\v4.0.30319\RegAsm.exe | 72 |
| C:\Windows\Microsoft.NET\Framework64\v4.0.30319\RegAsm.exe | 83 |
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.