sigmamediumHunting

C# IL Code Compilation Via Ilasm.EXE

Detects the use of "Ilasm.EXE" in order to compile C# intermediate (IL) code to EXE or DLL.

MITRE ATT&CK

defense-evasion

Detection Query

selection_img:
  - Image|endswith: \ilasm.exe
  - OriginalFileName: ilasm.exe
selection_cli:
  CommandLine|contains:
    - " /dll"
    - " /exe"
condition: all of selection_*

Author

frack113, Nasreddine Bencherchali (Nextron Systems)

Created

2022-05-07

Data Sources

windowsProcess Creation Events

Platforms

windows

References

Tags

attack.defense-evasionattack.t1127

Raw Content

title: C# IL Code Compilation Via Ilasm.EXE
id: 850d55f9-6eeb-4492-ad69-a72338f65ba4
status: test
description: Detects the use of "Ilasm.EXE" in order to compile C# intermediate (IL) code to EXE or DLL.
references:
    - https://lolbas-project.github.io/lolbas/Binaries/Ilasm/
    - https://www.echotrail.io/insights/search/ilasm.exe
author: frack113, Nasreddine Bencherchali (Nextron Systems)
date: 2022-05-07
modified: 2022-05-16
tags:
    - attack.defense-evasion
    - attack.t1127
logsource:
    product: windows
    category: process_creation
detection:
    selection_img:
        - Image|endswith: '\ilasm.exe'
        - OriginalFileName: 'ilasm.exe'
    selection_cli:
        CommandLine|contains:
            - ' /dll'
            - ' /exe'
    condition: all of selection_*
falsepositives:
    - Unknown
level: medium