SigmaHQ/rules/proxy/proxy_empty_ua.yml
2020-09-15 07:02:30 -06:00

27 lines
667 B
YAML

title: Empty User Agent
id: 21e44d78-95e7-421b-a464-ffd8395659c4
status: experimental
description: Detects suspicious empty user agent strings in proxy logs
author: Florian Roth
date: 2017/07/08
modified: 2020/09/03
references:
- https://twitter.com/Carlos_Perez/status/883455096645931008
logsource:
category: proxy
detection:
selection:
# Empty string - as used by Powershell's (New-Object Net.WebClient).DownloadString
c-useragent: ''
condition: selection
fields:
- ClientIP
- c-uri
- c-useragent
falsepositives:
- Unknown
level: medium
tags:
- attack.defense_evasion
- attack.command_and_control
- attack.t1071.001