Re: Virus/trojan tunnel out from behind firewall?

From: David Carmean (dlcat_private)
Date: Sun Feb 24 2002 - 23:07:15 PST

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    On Sun, Feb 24, 2002 at 10:22:12PM -0600, Rich Puhek wrote:
    > David Carmean wrote:
    
    > > Have there been any cases of a trojan/virus/etc tunnelling out from
    > > behind a firewall and thus providing an attacker a way into the
    > > "chewy center"?
    > 
    > Do you mean a trojan/virus that actively establishes a tunnel through
    > SSH, etc to an outside machine as a method of bypassing a stateful
    > firewall?
    >
    > Or do you just mean that a trojan/virus/etc has provided an opening
    > despite the firewall?
    > 
    > I'd also consider the gray areas in between, like worms/trojans that
    > transfer into (passwds, etc) back through SMTP, HTTP, or IRC.
    
    I was thinking more of the first example, an ssh/stunnel/other tunnel 
    out from the infected host to some other compromised box, which would 
    give an attacker a wormhole into the center of a corporate network.  
    In realtime.
    
    For sites which allow unrestricted outbound connections, it would 
    probably be impossible to detect if the trojan did nothing else 
    destructive to arouse suspicion. 
    
    
    
    
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