Detection rules › Sigma

Curl Download And Execute Combination

Status
test
Severity
high
Log source
category process_creation, product windows
Author
Sreeman, Nasreddine Bencherchali (Nextron Systems)
Source
github.com/SigmaHQ/sigma

Adversaries can use curl to download payloads remotely and execute them. Curl is included by default in Windows 10 build 17063 and later.

MITRE ATT&CK coverage

Telemetry coverage

Rule body

title: Curl Download And Execute Combination
id: 21dd6d38-2b18-4453-9404-a0fe4a0cc288
status: test
description: Adversaries can use curl to download payloads remotely and execute them. Curl is included by default in Windows 10 build 17063 and later.
references:
    - https://medium.com/@reegun/curl-exe-is-the-new-rundll32-exe-lolbin-3f79c5f35983 # Dead Link
author: Sreeman, Nasreddine Bencherchali (Nextron Systems)
date: 2020-01-13
modified: 2024-03-05
tags:
    - attack.stealth
    - attack.t1218
    - attack.command-and-control
    - attack.t1105
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        CommandLine|contains|windash: ' -c '
        CommandLine|contains|all:
            - 'curl '
            - 'http'
            - '-o'
            - '&'
    condition: selection
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    CommandLine|contains|windash: ' -c '
    CommandLine|contains|all:
        - 'curl '
        - 'http'
        - '-o'
        - '&'

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
CommandLinematch
  • -c transforms: windash corpus 13 (sigma 13)
  • &
  • -o corpus 3 (sigma 3)
  • curl corpus 17 (sigma 11, elastic 5, chronicle 1)
  • http corpus 52 (sigma 34, elastic 15, chronicle 2, splunk 1)
field:"CommandLine" kind:match