On February 13, 2002 22:58 pm, Dave Dittrich wrote: [snip] > > This attack used a variation of a TCP based reflection attack that is > not widely known to exist in the wild. Steve's early analysis of the > attack in included below (Appendix A). > > While there may be a new (D)DoS program "in the wild" to implement this > attack, the risks and methods have been known for two or more years > and some simple modifications to existing tools, and a good list of > high-capacity routers, switches, and servers, could affect an attack > of this type. I have two web servers on different networks that have been receiving this type of traffic for the last 2 or 3 weeks. The same source IP's hit both hosts at about the same time. This is low rate traffic and generates ACK's back to the target. I have been logging this activity for about two weeks and have captured some of the packets. I suspect that more than one machine have the same reflector host list based on the varying times of day when activity occurs. A partial solution is for network operators (more likely ISP's) to do egress filtering to ensure that only IP source addresses that belong to their network leave their network. John Elliott ---------------------------------------------------------------------------- This list is provided by the SecurityFocus ARIS analyzer service. For more information on this free incident handling, management and tracking system please see: http://aris.securityfocus.com
This archive was generated by hypermail 2b30 : Thu Feb 14 2002 - 08:48:53 PST