Re: CodeRed Observations.

From: Ţórhallur Hálfdánarson (tolliat_private)
Date: Thu Mar 13 2003 - 15:22:54 PST

  • Next message: larosa, vjay: "RE: CodeRed Observations."

    Hi
    
    When you notice these packets, are there *never* SYN packets?
    
    I'm thinking: firewall at other end blocking only SYN outbound (quite unlikely if you're getting it by hundreds, but, hey, one never knows :)
    
    
    Regards,
    Tolli
    
    -*- larosa, vjay <larosa_vjayat_private> [ 2003-03-13 18:28 ]:
    > Some of the systems respond to a ping, none respond to
    > any HTTP requests. It doesn't mean that they are not 
    > firewalled from incoming traffic though. 
    > 
    > vjl
    > 
    > -----Original Message-----
    > From: Rob Shein [mailto:shotenat_private]
    > Sent: Thursday, March 13, 2003 12:13 PM
    > To: 'larosa, vjay'; incidentsat_private
    > Subject: RE: CodeRed Observations.
    > 
    > 
    > Ok, here's another thought...is the IP address that the traffic apparently
    > originates from actually accessible, and is it running a vulnerable IIS?  I
    > would think that if someone wanted to hide an attack, they'd hide amidst a
    > huge amount of varied attack noise, rather than something so homogenous (and
    > expected) as this.
    > 
    > > -----Original Message-----
    > > From: larosa, vjay [mailto:larosa_vjayat_private] 
    > > Sent: Thursday, March 13, 2003 11:59 AM
    > > To: 'Rob Shein'; larosa, vjay; incidentsat_private
    > > Subject: RE: CodeRed Observations.
    > > 
    > > 
    > > Hi Rob,
    > > 
    > > I'm not saying that the worm is stateless. I am saying that 
    > > the traffic I am seeing at my border firewalls (codered 
    > > strings) are not part of established sessions (stateless). I 
    > > was just trying 
    > > to figure out if this had something to do with the new 
    > > outbreak, or if 
    > > somebody is trying to trick me in to ignoring packets they 
    > > don't want me to see, so they are throwing a stateless attack 
    > > at me to hopefully hide the real attack under the guise of 
    > > CodeRed. Call me crazy but paranoia is my middle name.
    > > 
    > > vjl
    > > 
    > > 
    > > -----Original Message-----
    > > From: Rob Shein [mailto:shotenat_private]
    > > Sent: Thursday, March 13, 2003 11:50 AM
    > > To: 'larosa, vjay'; incidentsat_private
    > > Subject: RE: CodeRed Observations.
    > > 
    > > 
    > > I'd be careful and make sure, if I were you.  I don't think 
    > > that the worm is stateless, as it wouldn't be able to spread 
    > > if it just sent data over TCP without establishing the 
    > > handshake first.  When you just PSH without handshaking 
    > > first, your data gets rejected.
    > > 
    > > > -----Original Message-----
    > > > From: larosa, vjay [mailto:larosa_vjayat_private]
    > > > Sent: Thursday, March 13, 2003 11:32 AM
    > > > To: 'Rob Shein'; larosa, vjay; incidentsat_private
    > > > Subject: RE: CodeRed Observations.
    > > > 
    > > > 
    > > > There are no filters in place for viewing the firewall logs.
    > > > Even if there were, the attacks I am seeing are even targeted 
    > > > to IP addresses that are not up and on-line in my network. So 
    > > > how would a "get default.ida?XXX" string be sent to a host that 
    > > > is,
    > > > 
    > > > a) Not up on the network.
    > > > b) Behind a firewall that blocks ALL incoming port 80.
    > > > 
    > > > If there is no three way handshake to set up a TCP session
    > > > I should not see this data trying to flow to my hosts (Dead
    > > > IP's or even live IP's). The traffic I am seeing is stateless 
    > > > (Stick/Snot). 
    > > > 
    > > > vjl
    > > > 
    > > > -----Original Message-----
    > > > From: Rob Shein [mailto:shotenat_private]
    > > > Sent: Thursday, March 13, 2003 10:57 AM
    > > > To: 'larosa, vjay'; incidentsat_private
    > > > Subject: RE: CodeRed Observations.
    > > > 
    > > > 
    > > > Check your filters.  You might be looking at traffic through
    > > > a selection filter that doesn't show the handshake, so that 
    > > > you can concentrate on the content that passes back and 
    > > > forth.  That's what I usually find to be the case when 
    > > > someone makes this kind of observation...
    > > > 
    > > > > -----Original Message-----
    > > > > From: larosa, vjay [mailto:larosa_vjayat_private]
    > > > > Sent: Wednesday, March 12, 2003 7:48 PM
    > > > > To: 'incidentsat_private'
    > > > > Subject: FW: CodeRed Observations.
    > > > > 
    > > > > 
    > > > > > Hello,
    > > > > > 
    > > > > > I have been watching this recent spike in CodeRed 
    > > activity and one 
    > > > > > thing I am noticing is the lack of TCP session
    > > > establishment. I am
    > > > > > seeing common get strings like this showing
    > > > > > up at my firewalls without ever establishing a TCP three
    > > > > way handshake. I
    > > > > > have seen several
    > > > > > hundred packets with in the last two days similar to this
    > > > > at my firewalls.
    > > > > > 
    > > > > > 47 45 54 20 2F 64 65 66 61 75 6C 74 2E 69 64 61  GET
    > > > > /default.ida 3F
    > > > > > 58 58 58 58 58 58 58 58 58 58 58 58 58 58 58
    > > > > ?XXXXXXXXXXXXXXX 58 58
    > > > > > 58 58 58 58 58 58 58 58 58 58 58 58 58 58  XXXXXXXXXXXXXXXX
    > > > > 58 58 58
    > > > > > 58 58 58 58 58 58 58 58 58 58 58 58 58  XXXXXXXXXXXXXXXX 58
    > > > > 58 58 58
    > > > > > 58 58 58 58 58 58 58 58 58 58 58 58  XXXXXXXXXXXXXXXX
    > > > > > 
    > > > > 
    > > > 
    > > Snip------------------------------------------------------------------
    > > > > > ----
    > > > > > ------------------------------------------------------
    > > > > > 
    > > > > > I find it awfully strange that there is no handshake 
    > > (not even a 
    > > > > > single SYN to try and establish a session) but these
    > > > > packets show up
    > > > > > anyway. I also am not seeing an increase of port 80
    > > > > > scans in my firewall logs or with any of my IDS sensors. Is
    > > > > anybody else
    > > > > > out there seeing the
    > > > > > same things we are?
    > > > > > 
    > > > > > Thanks!
    > > > > > 
    > > > > > vjl
    > > > > > 
    > > > > > V.Jay LaRosa                           EMC Corporation
    > > > > > Information Security                  4400 Computer Dr.
    > > > > > (508)898-7433 office                  Westboro, MA 01580
    > > > > > (508)353-1348 cell                     www.emc.com
    > > > > > 888-799-9750 pager                   larosa_vjayat_private
    > > > > > 
    > > > > > 
    > > > > > 
    > > > > 
    > > > > --------------------------------------------------------------
    > > > > --------------
    > > > > 
    > > > > <Pre>Lose another weekend managing your IDS?
    > > > > Take back your personal time.
    > > > > 15-day free trial of StillSecure Border Guard.</Pre>
    > > > > <A href="http://www.securityfocus.com/stillsecure">
    > > > > http://www.securityfocus.com/stillsecure </A>
    > > > > 
    > > > > 
    > > > 
    > > 
    > 
    > ----------------------------------------------------------------------------
    > 
    > <Pre>Lose another weekend managing your IDS?
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    > 
    
    -- 
    Kveđja,
    Tolli
    tolliat_private
    
    ----------------------------------------------------------------------------
    
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    Take back your personal time.
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