sigmamediumHunting

Curl.EXE Execution With Custom UserAgent

Detects execution of curl.exe with custom useragent options

MITRE ATT&CK

command-and-control

Detection Query

selection_curl:
  - Image|endswith: \curl.exe
  - Product: The curl executable
selection_opt:
  CommandLine|contains:
    - " -A "
    - " --user-agent "
condition: all of selection_*

Author

frack113

Created

2022-01-23

Data Sources

windowsProcess Creation Events

Platforms

windows

References

Tags

attack.command-and-controlattack.t1071.001detection.threat-hunting

Raw Content

title: Curl.EXE Execution With Custom UserAgent
id: 3286d37a-00fd-41c2-a624-a672dcd34e60
status: test
description: Detects execution of curl.exe with custom useragent options
references:
    - https://curl.se/docs/manpage.html
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1071.001/T1071.001.md#atomic-test-2---malicious-user-agents---cmd
author: frack113
date: 2022-01-23
modified: 2023-02-21
tags:
    - attack.command-and-control
    - attack.t1071.001
    - detection.threat-hunting
logsource:
    category: process_creation
    product: windows
detection:
    selection_curl:
        - Image|endswith: '\curl.exe'
        - Product: 'The curl executable'
    selection_opt:
        CommandLine|contains:
            - ' -A '
            - ' --user-agent '
    condition: all of selection_*
falsepositives:
    - Scripts created by developers and admins
    - Administrative activity
level: medium