Full Disclosure mailing list archives

Re: I Got Hacked. Now What Do I Do?


From: Harlan Carvey <keydet89 () yahoo com>
Date: Wed, 19 May 2004 07:27:19 -0700 (PDT)

I have to apologize, as I didn't see the original post
in my inbox...could someone forward it to me?

Now one can't trust somewhat 50% of all Microsoft
Computers.

you trusted that many before? :)

Honestly though, it isn't a total writeoff.

Your data may well have been compromised - so you
need to run a validation
exercise after copying to a clean system but before
even starting a
webserver (or anything that could execute binaries
in your dataset) -

*Validate and sanity check database-data -
particularly any user/access
lists, and change passwords on any admin accounts.

*Validate and sanity check static html pages

* Recompile or upload from trusted sources any
binaries - they can't be
trusted - and validate / sanity check any scripts

* Ideally, if you have a DEV system that wasn't
compromised (many
organizations do) upload known-clean copies - just
be sure you didn't
backport any scripts or html pages from the "live"
server, nonsensical
though that might sound.

I am not going to say getting back to a 100%
trustworthy system is going
to be possible in a short term, but you should be
able to have 99%
confidence in your datasets and site pages within a
week.  Isn't going to
be cheap (in man hours, but that translates to money
in various ways)
either.

For the future, consider a bit of diversity and a
decent (DMZing)
firewall; if your boxes don't *have* exposed ports
other than 80, they can
only be compromised by an attack on that port, not
(say) 445.

Diversity doesn't mean dumping Windows if you are
wed to the platform (ie,
have an existing large investment in it) - but
consider Apache and PHP
rather than IIS and VBScript; they run just fine on
windows, will scale
with the company (so you can upgrade to non-windows
hardware in the future
if you need to) and are more common than IIS anyhow.

A decent firewall doesn't have to be expensive - for
entry level, you can
use a legacy PC with three network cards (inside,
outside, DMZ) and a
floppy (no hard) drive, then boot the fw with a LEAF
linux such as
Bering - from write protected floppy disks (and get
VPN support and a DNS
server thrown in for free :)

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