urg_flood

Explanation

The urg_flood event is designed to detect potential Urg Flood attacks on a network. An Urg Flood is a type of Denial-of-Service (DoS) attack that uses the Urgent Pointer (URG) flag in the TCP header. By overwhelming the target with a large number of packets with the URG flag set, the attacker can cause the target to become unresponsive or crash. This event is triggered when the number of packets with the URG flag set exceeds a certain threshold within a given time frame.

What to Look For

If the urg_flood event is triggered, it is important to examine the network traffic to determine the source of the attack. Look for patterns of TCP packets with the URG flag set, and analyze the source IP addresses and port numbers to identify potential attackers.

On the endpoint, check for any signs of network congestion or unresponsiveness that might be caused by the attack. It may also be necessary to implement mitigations such as blocking traffic from specific IP addresses or adjusting firewall rules to prevent further attacks.

Related MITRE ATT&CK Categories

Network Denial of Service, Technique T1498 - Enterprise
Endpoint Denial of Service, Technique T1499 - Enterprise