SigmaHQ/rules/proxy/proxy_empty_ua.yml
2019-12-07 00:11:33 +01:00

22 lines
546 B
YAML

title: Empty User Agent
id: 21e44d78-95e7-421b-a464-ffd8395659c4
status: experimental
description: Detects suspicious empty user agent strings in proxy logs
references:
- https://twitter.com/Carlos_Perez/status/883455096645931008
author: Florian Roth
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