[liberationtech] // The 'Kill Packet' - feedback wanted //

[Julian Oliver]

..on Mon, Feb 25, 2013 at 12:57:36PM -0600, Kyle Maxwell wrote:
> Off the top of my head, I'd have major security concerns around this
> because essentially this makes it very easy for an adversary to
> destroy all data on a system.

In fact only selected folders defined in the script on the server can be
deleted. As the code shows, there's no shell code going out in the payload..

It's true an adversary could steal your phone and aquire your unique key (which
is the only thing in the payload) but this would be a risk of running the
software on a phone without an encrypted hard disk. 

More so, as the code I posted shows any deletion on the server could trigger a
backup routine over SSH (scp) to a jailed/restricted user on a remote host,
deleting the server side SSH keys on completion.

Setup would go something like this:

    1/ User logs into https://mysite.com/killpacket.php on their server.
    2/ Defines directories for deletion and backup
    3/ Defines backup server, uploads a key
    4/ Defines a KILLSIG/passphrase and notes it directly onto phone
    5/ PHP updates deletion and backup server variables in the script
       or actually writes out the script directly if not SSH/CLI capable

> That said, in appropriate use cases, there's value for a kill switch
> or even a dead man's switch (if you don't take some action within
> every N hours, the device gets wiped).

Yes, I agree!

Thanks for your thoughts, 

Julian

> On Mon, Feb 25, 2013 at 12:37 PM, Julian Oliver <julian at julianoliver.com> wrote:
> 
> > Again, this is just a quick (1hr) sketch that could be developed into a simple
> > Android application with a big red button, or even a swipe pattern (more
> > discreet) that unlocks and sends the 'Kill Packet'. Security issues not
> > addressed in the sketch would be dealt with in turn.
> 
> -- 
> Kyle Maxwell [krmaxwell at gmail.com]
> http://www.xwell.org
> Twitter: @kylemaxwell
> --
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-- 
Julian Oliver
http://julianoliver.com
http://criticalengineering.org