Rule:
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Sid:
230

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Summary:
This event is generated when a DDoS Shaft client communicates with a Shaft handler.  It is also possible that this event may be generated when any host attempts to discover or detect a Shaft handler.

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Impact:
Attempted DDoS. If the listed source IP is in your network, it may be a Shaft client or a host attempting to discover Shaft handlers.  If the listed destination IP is in your network, it may be a Shaft handler.

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Detailed Information:
The Shaft DDoS uses a tiered structure of compromised hosts to coordinate and participate in a distributed denial of service attack. At the highest level, clients communicate with handlers to direct them to launch attacks.  A client may communicate with a handler via TCP destination port 20432.

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Affected Systems:
Any Shaft compromised host.

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Attack Scenarios:
A Shaft client needs to communicate with handlers to direct attacks.

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Ease of Attack:
Simple. Shaft code is freely available.

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False Positives:
A legitimate server port of 20432 will cause this rule to fire.  It may also create a false positive if port 20432 is selected as an FTP data port.

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False Negatives:
None Known.

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Corrective Action:
Perform proper forensic analysis on the suspected compromised host to discover the means of compromise.

Rebuild a confirmed compromised host.

Use a packet-filtering firewall to block inappropriate traffic to the network to prevent hosts from being compromised.


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Contributors:
Original rule written by Max Vision <vision@whitehats.com>
Sourcefire Vulnerability Research Team
Judy Novak <judy.novak@sourcefire.com>

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Additional References:

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