Re: ddos

[TMiller () NCIINC COM (Miller, Toby)]

All,
        IDS signatures are fine IF the attacker uses default settings on
tools like TFN and Trinoo. With all of these tools being open source, an
attacker can change any or all ports he/she wants. This will ensure
communications with the compromised systems will not be detected by IDS.
Therefore, we really can not always trust our IDS systems when it comes to
attacks such as these. In my opinion there is really no easy answer on how
to detect and protect. Knowing and reviewing your systems(including logs and
binaries) along with commerical products like firewalls, IDS systems along
with a solid security policy will be the one true way of protecting
ourselves against attacks like tfn or trinoo.
        

> -----Original Message-----
> From: Ron Gula [SMTP:rgula () SECURITYWIZARDS COM]
> Sent: Tuesday, February 15, 2000 7:26 AM
> To:   INCIDENTS () SECURITYFOCUS COM
> Subject:      Re: ddos
>
> At 10:50 PM 2/14/00 -0000, you wrote:
> > I wrote tests to detect trinoo, strat., and tfn about 2
> > months ago. They were going to be released with our security
> > analyzer for the next build, but in light of the problems as
> > of late we have them available for download.
>
> As long as people are talking about detecting these ddos attacks, it
> may be useful to tell you what we have been seeing with Dragon. We've
> been running signatures since Thanksgiving which look for tfn,trinno,
> tfn2k and a few other ddos attacks. We have seen a lot of people use
> the free tools which "discover" platforms that may have been compromised.
> Here is an example:
>
> bash-2.03# sum_event -n | grep TRINOO
> [TRINOO:CMD]              6553
> bash-2.03# mklog -l -e TRINOO:CMD | more
> ** Make Logs Tool - Copyright 1999 Network Security Wizards
> ** http://www.securitywizards.com
> ** Printing 'dragon.log' style data
> ** Printing events of type [TRINOO:CMD
> ** Date: Thursday February 10 2000
> 17:26:36  [I]  105.152.72.114  105.152.72.1    [TRINOO:CMD]
> (udp,dp=27444,sp=2209) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.2    [TRINOO:CMD]
> (udp,dp=27444,sp=2210) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.3    [TRINOO:CMD]
> (udp,dp=27444,sp=2211) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.5    [TRINOO:CMD]
> (udp,dp=27444,sp=2213) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.8    [TRINOO:CMD]
> (udp,dp=27444,sp=2216) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.10   [TRINOO:CMD]
> (udp,dp=27444,sp=2218) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.11   [TRINOO:CMD]
> (udp,dp=27444,sp=2219) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.12   [TRINOO:CMD]
> (udp,dp=27444,sp=2220) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.13   [TRINOO:CMD]
> (udp,dp=27444,sp=2221) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.23   [TRINOO:CMD]
> (udp,dp=27444,sp=2231) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.31   [TRINOO:CMD]
> (udp,dp=27444,sp=2239) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.32   [TRINOO:CMD]
> (udp,dp=27444,sp=2240) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.33   [TRINOO:CMD]
> (udp,dp=27444,sp=2241) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.34   [TRINOO:CMD]
> (udp,dp=27444,sp=2242) (bass.gula.net)
> 17:26:36  [I]  105.152.72.114  105.152.72.35   [TRINOO:CMD]
> (udp,dp=27444,sp=2243) (bass.gula.net)
>
> The sweep goes on for several Class C addresses.
>
> For TFN2K, several signatures have been deployed to look for TFN2K
> traffic on TCP, UDP and ICMP. Strangley enough, the game Halflife
> tends to false positive the UDP signature somewhat.
>
> Ron Gula, CTO
> Network Security Wizards, Inc.
> http://www.securitywizards.com