Florian Roth
34 lines
996 B
YAML
34 lines
996 B
YAML
title: Suspicious User Agent
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status: experimental
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description: Detects suspicious malformed user agent strings in proxy logs
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references:
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- https://github.com/fastly/waf_testbed/blob/master/templates/default/scanners-user-agents.data.erb
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author: Florian Roth
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logsource:
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category: proxy
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detection:
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selection:
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UserAgent:
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# Badly scripted UA
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- 'user-agent' # User-Agent: User-Agent:
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- '* (compatible;MSIE *' # typical typo - missing space
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- '*.0;Windows NT *' # typical typo - missing space
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- 'Mozilla/3.0 *'
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- 'Mozilla/2.0 *'
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- 'Mozilla/1.0 *'
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- 'Mozilla *' # missing slash
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- ' Mozilla/*' # leading space
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- 'Mozila/*' # single 'l'
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- '_'
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falsepositives:
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UserAgent:
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- 'Mozilla/3.0 * Acrobat *' # Acrobat with linked content
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condition: selection and not falsepositives
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fields:
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- ClientIP
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- URL
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- UserAgent
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falsepositives:
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- Unknown
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level: high
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