Worm attacks

Peter Van Epp vanepp at sfu.ca
Mon Jul 23 11:14:53 EDT 2001

> Gentle people,
>    Did any one catch any worm traffic this past week?
> I'd love to see the first 64 bytes, if anyone has any
> logs.  I'm guessing that Argus would have been the only
> technology to automatically audited worm traffic from the
> last wave.
> Carter
> Carter Bullard
> QoSient, LLC
> 300 E. 56th Street, Suite 18K
> New York, New York  10022
> carter at qosient.com
> Phone +1 212 588-9133
> Fax   +1 212 588-9134
> http://qosient.com

	Yep, I can likely supply argus logs. As well argus finds them just
fine. So far its found three that security focus has so far either missed
or not gotten to yet. It also sparked this (from my login article):

        A news break, as I type this (on July 19) the IIS red worm has broken
out. This provides a case study in using argus for unconventional things. A
CERT notification yesterday gave me my first infected machine. A look at the
argus log indicates a signature of many mostly 0 length connection attemtps to
off site web servers. So a quick perl script that takes the argus ra tool
output as input and selects accesses to port 80 not on any of my nets gets
written quickly. The source and destination ip addresses get stored in an
assocoative array indexed by source and destination ip address and then sorted.
As long as the source address is the same, increment a counter (because this
is a new destination access from this same host). Once the source address
changes store the source address in a new associative array indexed by the
remote host count. When the entire file has been processed, sort the array of
counts in reverse numeric order and write it to standard out. This is about a
page of perl and an hour or so of work. The output looks like this (with the
addresses obscured to protect the guilty):




        The first address (and 9 more like it across both our campuses) is a
machine affected with the iis red worm scanning other machines. The other two
hosts are normal accesses. This is a fine example of having all the data
passing through your network being very useful. A firewall would ignore this,
they were http accesses on port 80. There are reports the inital snort rule
wasn't catching all of these because of a rule mistake. The mark one eyeball
(after some thinking and data processing) has no problem picking the difficulty
out of the noise and a manual scan of the argus log verifies that this really
is the worm (again with addresses obscured) from the ra output itself:

Thu 07/19 06:56:44 s    tcp   1xx.yy.zzc.65.60806  -> aaa.    3
   0       0         0        REQ
Thu 07/19 06:56:44 s    tcp   1xx.yy.zzc.65.60791  ->   bb.    3
   0       0         0        REQ
Thu 07/19 06:56:44 s    tcp   1xx.yy.zzc.65.60813  ->    cc.    3
   0       0         0        REQ
Thu 07/19 06:56:44 s    tcp   1xx.yy.zzc.65.60768  ->    dd.    3
   0       0         0        REQ
       ... (lots more just like this. 100,535 of them in fact ...)

So whack this host off the network and proceed with our interrupted story.

Peter Van Epp / Operations and Technical Support 
Simon Fraser University, Burnaby, B.C. Canada

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