Detection rules › Sigma
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 coverage
| Tactic | Techniques |
|---|---|
| Execution | |
| Stealth |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
Rule body
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.execution
- attack.stealth
- 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
Stages and Predicates
Stage 0: condition
all of selection_*Stage 1: selection_img
selection_img:
- Image|endswith: '\ilasm.exe'
- OriginalFileName: 'ilasm.exe'
Stage 2: selection_cli
selection_cli:
CommandLine|contains:
- ' /dll'
- ' /exe'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
CommandLine | match |
| field:"CommandLine" kind:match |
Image | ends_with |
| field:"Image" kind:ends_with value:"\ilasm.exe" |
OriginalFileName | eq |
| field:"OriginalFileName" kind:eq value:"ilasm.exe" |