Detection rules › Sigma

Curl.EXE Execution

Status
test
Severity
low
Log source
product windows, category process_creation
Author
Florian Roth (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Detects a curl process start on Windows, which could indicates a file download from a remote location or a simple web request to a remote server

MITRE ATT&CK coverage

TacticTechniques
Command & ControlT1105 Ingress Tool Transfer

Event coverage

ProviderEventTitle
SysmonEvent ID 1Process creation

Rule body yaml

title: Curl.EXE Execution
id: bbeaed61-1990-4773-bf57-b81dbad7db2d
related:
    - id: e218595b-bbe7-4ee5-8a96-f32a24ad3468 # Suspicious curl execution
      type: derived
status: test
description: Detects a curl process start on Windows, which could indicates a file download from a remote location or a simple web request to a remote server
references:
    - https://web.archive.org/web/20200128160046/https://twitter.com/reegun21/status/1222093798009790464
author: Florian Roth (Nextron Systems)
date: 2022-07-05
modified: 2023-02-21
tags:
    - attack.command-and-control
    - attack.t1105
    - detection.threat-hunting
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        - Image|endswith: '\curl.exe'
        - Product: 'The curl executable'
    condition: selection
falsepositives:
    - Scripts created by developers and admins
    - Administrative activity
level: low

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    - Image|endswith: '\curl.exe'
    - Product: 'The curl executable'

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
  • \curl.exe corpus 30 (sigma 30)
Producteq
  • The curl executable corpus 5 (sigma 5)