From: Harlan Carvey (keydet89yahoo.com)
Date: Fri Aug 27 2004 - 05:41:20 CDT

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> We cleaned up all of these machines and rebuilt each
> of them from
> scratch, with all the latest patches. The IDS/IPS at
> the edge of our
> network, does not seem to be catching the bots which
> are causing
> these.

When you say IDS/IPS, which are you referring to? If
IDS, remember...they are signature-based. One of the
biggest problems with employing such a technology is
not understanding that it only detects those things
that it has signatures for...

> After one week, I have 50 machines which are
> compromised by the same
> bot, and some of them are the same as the previous
> list of machines.

That tends to happen in situations in which no root
cause analysis was done.

> Now a host-based firewall is a very tough option
> for us, since we are
> a university with around 30,000 computers and under
> different
> departments. Does anyone know what bots are causing
> these and any IDS signatures for these.

Well, given the banner you provided, it would seem
that you could write one of your own. Does your IDS
product provide the facility for such a thing?

> We are using a couple of IDS such as snort and
> Dragon and Intrushield, Any help for this is
> appreciated.

My earlier question was rhetorical...

> I did have a look at one of these
> machines and from what I see, there are a couple of
> files which seem to be causing this.
> there is a csmss.exe file which is listening on the
> port 6544.. The
> machine is also running a remote server.
> before csmss.exe, a file ServNT.exe seems to have
> been executed, which
> might have caused a sequence of events.. there is a
> batch file , which
> using the registry runs a remote admin server at
> startup. then we got
> a number of files which are used to show the banner,
> hide the files .
> If I could find out how did they get inside the
> system, because most
> of the infected machines were running fully patched
> Windows XP with
> latest Norton Antivirus definitions.?

Patches aren't the be-all-and-end-all...there's more
to security than that. There are other avenues into
systems such as email and the browser...avenues that
may not be covered by patches.

> All of those machines are running either Windows
> 2000 professional or XP professional.
> 2 machines wer analysed, one of which was completely
> ptched and had
> all the latest virus definitions from Norton,
> another machine was not
> patched and no virus updates were present.. But the
> state of affairs
> at both the machines was the same.. themessage sent
> before contains
> the details..
> on more analysis, I found csmss.exeto be a part of
> W32.Dedler
> Trojan.. but how it got inside the system is
> anyone's guess..

Perhaps not...I went to the Symantec site and looked
up "Dedler"...it's not a Trojan...it's a worm.
http://securityresponse.symantec.com/avcenter/venc/data/w32.dedler.worm.html

Interesting thing about the write-up at the site:
"4. Copies the following files to open network
shares:"

There wasn't any detail in your description regarding
your domain setup, but maybe that helps a little bit
in explaining how so many systems were infected. I
know the Symantec writeup doesn't jive exactly with
your description, but based on what Norton detected,
it's a start. It might also go toward explaining why
so many machines were reinfected...

> None of them was running IIS.

Ok...I'm not sure where that plays into all this...but
ok...

Good luck.

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