Security Incidents mailing list archives

Re: 1,800 files missing from system32


From: Harlan Carvey <keydet89 () yahoo com>
Date: Thu, 14 Oct 2004 12:29:15 -0700 (PDT)

Ah, the much anticipated Carvdog reply on the
incidents list. I was afraid I'd get one. ;-)

Well, if that's the case, you should have specified
that you didn't want to hear from me.

BTW...that's Carvdawg to you...  ;-)
  
To the best of my knowledge WFP cannot be disabled
post SP2. 

[snip]

Based on that, I believe WFP to be functional. 

I would say that based on the messages you were seeing
in the Event Log, that's enough to show that WFP
is/was still working.  But your understanding is
correct, as well...except that there is reportedly
another way to disable WFP by modifying the applicable
(based on os version) DLL files w/ a hex editor.  I've
referenced this method in my book.

If the
information above is not true please let me know.
Being able to dynamically enable and disable WFP
would prove very useful to our developers.

Yes, you're correct with regards to the information
you listed...install a debugger, modify the Registry
entry appropriately, etc.

I failed to mention that these events have occurred
over about 5 months. I think the odds of Symantec
missing a bug that does this kind of damage, but has
been around for that long, are low. I think current
AV
sigs (with file system real time protection) should
prevent the system from getting infected and the AV
engine from being disabled. I'm not going to bet a
month's salary on that, though. Unfortunately the
tech
on site did not re-scan the host. He attempted to
use
TrendMicro's HouseCall, but bandwidth was such that
he could not get it to work. 

I'm with you 100% on needing to get time to analyze
the systems. On the last one we were able to run
diagnostics for MS support and provided them with
about 20MB of captured data. They just scratched
their
heads and said it "looks virus like". I advocated
for
waiting before rebuilding this one, as it was our
best
chance to date to get a good analysis done, but that
was not approved. I'm trying to get the word out to
our techs that if they should run across one of
these
systems again that it should not get immediately
reloaded.

Here is our auditing policy on the DCs

Audit account logon events :: Success, Failure
Audit account management :: Success, Failure
Audit directory service access :: Failure
Audit logon events :: Success, Failure
Audit object access :: Failure
Audit policy change :: Success, Failure
Audit privilege use :: Failure
Audit process tracking :: No Auditing
Audit system events :: Success, Failure

Except for not auditing directory service access,
non-DCs are the same. Do you think this would
normally
be an adequate policy? Are there any changes you
would recommend?

Well, since in most cases, people/admins aren't
running programs on the DC (ie, Solitaire, browsers,
etc), you shouldn't have a problem in setting both
success and failure auditing on process tracking.  You
may also want to increase the size of the logs, but
the most important thing would be to regularly review
the log entries...for that, using a syslog client such
as NTSyslog to send the entries to a system running
the Kiwi Syslog Server would be a great idea.

All files that WFP logged were exe, tlb, dll or ocx
files.

...could be a virus...but there's still nothing
definitive.

We have seen problems with Sasser like activity on
these networks in the past, and at two locations we
applied the patch for MS04-011 and resolved those
issues. So, yes, it was a guess but it was also
based on past malware activity on these LANs. 

I've been looking around on a couple of AV sites, and
as yet, haven't found anything that correlates the
activity you mention to a version of a Sasser-like
worm.  That doesn't mean that it's not the case...just
that I haven't seen anything like that yet.

They have no
inbound access allowed from the Internet, but they
are
large enough that an infected laptop can still make
its way onto the LAN and wreak havoc. It's happened
before, though incidents on these LAN are relatively
rare.

Yeah, that's an avenue that we see all the time.

In the event we manage to get to one of these hosts
before it completely dies (when they are like this a
reboot kills them) what tools would you recommend we
run?

Get tlist.exe from the Microsoft Debugger Tools (*NOT*
the resource kit).  Run this with the '-c' switch to
get the command lines of all the processes running on
the system.  Look for anything unusual.  

Get network connection information using a clean
version of netstat, and include openports.exe from
DiamondCS (better than fport).  If you have access to
an admin account on the running system, use portqry
v.2.0 from Microsoft.  The combination of these tools
will give you a pretty complete view of network
connections and the processes associated with each
connection.  You might also use tcpvcon.exe from
SysInternals.

If you prefer a GUI approach, use Process Explorer and
TCPView from SysInternals.

In case that doesn't provide you with enough info
(;-)) check the startup locations using AutoRuns from
SysInternals, or the Silent Runner .vbs script (from
silentrunners.org).  

You might also consider running anti-spyware tools,
and keeping a log of their findings.

Basically, what you're looking for are any unusual
processes, network connections, etc., the may at least
give you a clue as to what's happening.

Hope that helps,



=====
------------------------------------------
Harlan Carvey, CISSP
"Windows Forensics and Incident Recovery"
http://www.windows-ir.com
http://groups.yahoo.com/group/windowsir/

"Meddle not in the affairs of dragons, for
you are crunchy, and good with ketchup."

"The simplicity of this game amuses me. 
Bring me your finest meats and cheeses."
------------------------------------------


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