Sigma rule: Suspicious Use of CSharp Interactive Console

Rule

Title

Suspicious Use of CSharp Interactive Console

Status

test

Level

high

Author

Michael R. (@nahamike01)

Date

2020-03-08

Modified

2022-07-14

File

rules/windows/process_creation/proc_creation_win_csi_use_of_csharp_console.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the execution of CSharp interactive console by PowerShell

Log source

product

windows

category

process_creation

Detection

selection:
    Image|endswith: '\csi.exe'
    ParentImage|endswith:
        - '\powershell.exe'
        - '\pwsh.exe'
        - '\powershell_ise.exe'
    OriginalFileName: 'csi.exe'
condition: selection

False positives (as the rule lists them)

• Possible depending on environment. Pair with other factors such as net connections, command-line args, etc.

Tags

• attack.execution
• attack.stealth
• attack.t1127

MITRE ATT&CK ids this rule names

• T1127

References

• https://redcanary.com/blog/detecting-attacks-leveraging-the-net-framework/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_csi_use_of_csharp_console.yml