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 | A4EB36BAE72C5CB7392F2B85609D4A7E |
| SHA1 | 5C58053A3A18C0226B98A4AC7E7320581300B6C9 |
| SHA256 | DC45704BA97D974D157C1C4A27DBA402AFA595EAC2468D8DEF2EE8D0A2EE9A81 |
| SHA384 | D01ADC95EF11EDBFD6B1EA1D926A7030A9782B655C641CACE6D5529287D2396E6226DB90DFD0F30FADD9E303A5962668 |
| SHA512 | 8EBDD20B7C1EE87AA3766D812960B0D8CFA0A6BA6E371F730E589895D202DD540EB475F69940261C1532E90D1030370E9EB5102CADBF6E546F99B350DE79B95A |
| SSDEEP | 768:/8XcJiMjm2ieHFYPyCsSuJbn8dBhFwjSMF6Iq8KSYDKvc7qWk81:zYMaNyFYPYSAb8dBnWHsPDKvcN91 |
| PESHA1 | EC1B45DF76B912BCAB4A524A47D2C3EF82EC98B1 |
| PE256 | AC8DAEF33BF5CFD6A93FD30A9100A1F89413C0794F31A91F716A8CB4907BAA0D |
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\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:
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: 64-bit
File Scan
- VirusTotal Detections: 0/75
- VirusTotal Link: https://www.virustotal.com/gui/file/dc45704ba97d974d157c1c4a27dba402afa595eac2468d8def2ee8d0a2ee9a81/detection
File Similarity (ssdeep match)
| File | Score |
|---|---|
| C:\Windows\Microsoft.NET\Framework\v4.0.30319\RegAsm.exe | 83 |
| C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\RegAsm.exe | 75 |
| 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.