Rule: 

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Sid: 
111-12

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Summary: 
This event is generated when the pre-processor stream4
detects network traffic that may constitute an attack.

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Impact: 
This may indicate scanning activity.

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Detailed Information:
The pre-processor stream4 has detected network traffic that may indicate
a scan is in progress. In this case, indications are that the tool nmap
is being use to determine the operating system of the target host.

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Affected Systems:
	All systems

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Attack Scenarios: 
An attacker may utilize scanning techniques to determine possible points
of exploitation against a host.

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Ease of Attack: 
Simple. Many scanning tools exist.

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False Positives:
None Known.

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False Negatives:
None Known.

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Corrective Action:
Check the target host for signs of compromise.

Ensure the system is up to date with any appropriate vendor supplied patches.

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Contributors:
Martin Roesch <roesch@sourcefire.com>
Sourcefire Vulnerability Research Team
Nigel Houghton <nigel.houghton@sourcefire.com>

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Additional References:

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