Detection rules › Sigma

Potential Application Whitelisting Bypass via Dnx.EXE

Status
test
Severity
medium
Log source
product windows, category process_creation
Author
Beyu Denis, oscd.community
Source
github.com/SigmaHQ/sigma

Detects the execution of Dnx.EXE. The Dnx utility allows for the execution of C# code. Attackers might abuse this in order to bypass application whitelisting.

MITRE ATT&CK coverage

Event coverage

Rule body yaml

title: Potential Application Whitelisting Bypass via Dnx.EXE
id: 81ebd28b-9607-4478-bf06-974ed9d53ed7
status: test
description: |
    Detects the execution of Dnx.EXE. The Dnx utility allows for the execution of C# code.
    Attackers might abuse this in order to bypass application whitelisting.
references:
    - https://lolbas-project.github.io/lolbas/OtherMSBinaries/Csi/
    - https://enigma0x3.net/2016/11/17/bypassing-application-whitelisting-by-using-dnx-exe/
author: Beyu Denis, oscd.community
date: 2019-10-26
modified: 2024-04-24
tags:
    - attack.stealth
    - attack.t1218
    - attack.t1027.004
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith: '\dnx.exe'
    condition: selection
falsepositives:
    - Legitimate use of dnx.exe by legitimate user
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    Image|endswith: '\dnx.exe'

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Imageends_with
  • \dnx.exe corpus 3 (sigma 3)