Re: The "unplug the cord" dilemma

From: Chuck Swiger (cswigerat_private)
Date: Sun Mar 30 2003 - 08:26:26 PST

  • Next message: Valdis.Kletnieksat_private: "Re: The "unplug the cord" dilemma"

    Omar Herrera wrote:
    [ ... ]
    > Some issues:
    > Point 3 should be decided as fast as possible no matter the decision
    > taken (forensic policies and procedures should be in place already). 
    
    This point is well worth repeating.
    
    With regard to the Subject of this thread, it's useful to note that a 
    compromised system may be actively doing something harmful (like being 
    used as a DoS slave amplifier), it may be doing something passively 
    harmful (like sniffing the local networks for passwords/CC info/etc), or 
    it just might be providing resources to unauthorized users (disk space, 
    bandwidth, say if it's being used to host wares as an FTP server, or a 
    IRC bouncer), or it might be doing nothing at all.
    
    And the compromised system could range from air-traffic control systems 
    (providing critical services with human life potentially at risk if the 
    system is taken down abruptly; case #1 below), to developer test 
    machines, normal workstations, or spare hardware that could be taken 
    down permanently, at any time, with no (serious) adverse consequences.
    
    Whether you should take a specific action, whether it be rebooting the 
    machine cleanly, yanking the power cord immediately, or anything else, 
    should take both the importance of continued uptime and the severity of 
    the malicious activity-- or lack of activity-- currently taking place.
    
    If a user calls you over and says "hey, I double-clicked on this message 
    that said ILoveYou, and all of a sudden, my hard drive starting freaking 
    out", pulling the power cord before the worm finishes mangling all of 
    the local images and starts hunting for network drives to damage would 
    be a good move even in hindsight.  And that's what it comes down to: you 
    plan ahead so that you don't do things you end up regretting in hindsight.
    
    For example, whatever else you do, be *sure* to unplug the ethernet 
    cable (or sandbox the machine behind a tight firewall, on put it on a 
    test network, etc) before you power up the compromised system.  If the 
    machine is configured to do certain things upon system boot-- like email 
    a sniffer logfile containing passwords see on the local subnet to the 
    guy who r00t'ed the box-- and the machine is still connected to the 
    outside world, you will be sad.
    
    >  If taking decision C, could the company argue that by isolating the
    > system it is not failing to perform with due diligence?
    >  Two cases for analysis: 
    > 	* A critical system in an airport that controls air traffic 
    > 	* The mail server of an ISP where no backup or replacement is
    > available at the time
    
    The second case means that the organization didn't already have a 
    secondary MX in place, which seems unlikely for something which calls 
    itself an "ISP", but losing a reader box and not having an adequate 
    replacement lying around might happen.  Losing an SMTP relay just means 
    that other machines have to queue your mail until you do get a 
    replacement up; not a big deal, usually.
    
    -- 
    -Chuck
    
    
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