Re: viruses that have been cleaned or quarantined

["Garmon, Joel" <garmonjs () WFU EDU>]

Very good thread.

There is another nuance that I consider in reviewing AV alerts -- was it
caught in a real time scan (meaning the first time the file was downloaded
or used and stopped before executing) or in a periodic scan (daily or
weekly scan which means the virus has been on the system for a while and
already executed)

We also have special groups for departments that handle PII and have alerts
set up so we know when any virus hits these groups.  We review every alert
associated with PII.  This is a team effort between security, service desk,
and desktop support..


Thank you,

Joel Garmon
Director Information Security
Wake Forest University
336-758-2972

http://infosec.wfu.edu/


On Wed, Jun 21, 2017 at 4:52 PM, Kevin Wilcox <wilcoxkm () appstate edu> wrote:

> On 21 June 2017 at 15:50, Chelsie Power <cpower () csusm edu> wrote:
>
> > If your virus scanner has cleaned or quarantined a virus/malware/etc., do
> > you do any additional scanning or followup on the endpoint? I know virus
> > definitions, though up to date, may potentially just be catching a virus
> > that have lived on the machine for several months and had only been
> recently
> > identified. Do you trust that "cleaned" means it took care of any damage
> > that had been done, if any?
>
> Chelsie -
>
> I see no difference between AV and IDS. The idea that AV can "clean" a
> system is one that I'd like to see eradicated.
>
> That's not to say that it's impossible - just that it takes known-good
> cryptographic hash values for every file on the system, a trusted
> off-system scanning agent and good alerting when something changes.
> That's before having the same thing in place for registry hives, the
> ability to detect/audit ADSs, etc.
>
> If AV alerts on anything, and I can't otherwise determine it's a false
> positive, it's a re-image of the system. Again, AV alerts are treated
> the same as IDS alerts. There are some exceptions where it's profile
> removal/recreation but generally speaking that's insufficient for most
> of our environment.
>
> One massive hole to that approach - we backup data, re-image and
> restore. If something is hiding in one of the backed-up files, it
> comes back on the newly-built system.
>
> It's certainly not perfect and needs some work but I've done too many
> forensic examinations of systems to trust that AV can do anything
> beyond alerting on 25% of the stuff that's out there.
>
> kmw