Event ID - 15104

Event Id15104
SourceMicrosoft ISA Server Report Generator
DescriptionISA Server detected a port scan attack from Internet Protocol (IP) address %1. A well-known port is any port in the range of 1-2048.
Event InformationAccording to Microsoft

Cause:
A possible well-known port scan attack was attempted against a computer protected by ISA Server. This event occurs when an attempt is made to scan ports on this computer in order to detect the services running on these ports.
Resolution:
If logging for dropped packets is enabled, you can view details of this attack in the Firewall log in the log viewer. You can use this log to monitor any further intruder activity. To do this, in the console tree of ISA Server Management, click Monitoring. In the Logging tab, edit the log filter to view the relevant details. Take additional steps against intruder activity. For example, you may want to add access rules denying traffic from the source of the intrusion. To do this, in the console tree of ISA Server Management, click Firewall Policy. On the Tasks tab, click Create Access Rule.
Reference LinksEvent Id:15104 Source Id:Microsoft ISA Server Report Generator

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