Ethical Hacking

Learn to find vulnerabilities before the bad guys do! Gain real world hands on hacking experience in our state of the art hacking lab. Course designed and taught by expert instructors with years of penetration testing experience. 12 student maximum in every class. Certification attempt included in every package.
Computer Forensics Training at InfoSec Institute

Gain the in-demand skills of a certified computer examiner, learn to recover trace data left behind by fraud, theft, and cybercrime perpetrators. Discover the source of computer crime and abuse at your organization so that it never happens again. All of our class sizes are guaranteed to be 12 students or less to facilitate one-on-one interaction with one of our expert instructors.




Network Security Security-Basics
[Top] [All Lists]

RE: DoS Attackers using only udp and icmp protocol?

Subject: RE: DoS Attackers using only udp and icmp protocol?
Date: Mon, 12 Feb 2007 08:46:53 -0800
Could this the result of a spoofed IP source smurf attack or some other
amplification attack?

-----Original Message-----
From: listbounce@securityfocus.com [mailto:listbounce@securityfocus.com]
On Behalf Of krymson@gmail.com
Sent: Friday, February 09, 2007 12:16 PM
To: security-basics@securityfocus.com
Subject: Re: DoS Attackers using only udp and icmp protocol?

TCP DoS attacks are quite common, especially SYN floods. Because systems
listening on TCP for the 3-way handshake have a time-out while they wait
for the completion of the handshake after a SYN is first received, you
can exhaust resources on the system be flooding lots of SYNs and just
not completing the handshake. You could even complete the handshake and
flood that way as well.

I will throw an opinion out that might be wrong, but I feel TCP-related
floods tend to be aimed at exhausting TCP-listening resources on a
target. UDP and ICMP floods tend to also target saturation of the
target's network bandwidth.


<- snip ->

I have monitored that some DoS attack which generates large bps(over
1Gbps) 
against my network.
and I can see that all dos related packets are udp and icmp not tcp.

In the point of view attacker, 
Is it impossible that generates lots of packets and large packets using
tcp 
without 3 way handshake?


DISCLAIMER: This message (including any files transmitted with it) may contain 
confidential and / or proprietary information, is the property of Interactive 
Data Corporation and / or its subsidiaries and is directed only to the 
addressee(s). If you are not the designated recipient or have reason to believe 
you received this message in error, please delete this message from your system 
and notify the sender immediately. An unintended recipient's disclosure, 
copying, distribution or use of this message, or any attachments, is prohibited 
and may be unlawful.

<Prev in Thread] Current Thread [Next in Thread>