I disagree slightly. But first a few definitions of these two objects as I see them in STIX v2:
Sighting – One or more Observable instances combined with context, describing something ‘interesting’ that you have seen.
Indicator – One or more Observable patterns combined with context, describing something to look for, that if found indicates that some
potential scenario is happening (to a certain level of confidence).
I see these as two independent things. In my opinion these two things have been conflated together with STIX v1.x, meaning that a Sighting
is of an Indicator. This is a restriction of where the Sighting object has historically lived in STIX v1.x, but doesn’t necessarily need to be the case in STIX v2.0. I personally would like to see their close relationship broken apart in STIX v2, to give us
a bit more freedom. What do I mean by that?
Use Case
·
Org A has seen something weird on their network. There is an odd encoded _javascript_ line in HTML emanated from weirdsite.com.
Org A packages up a Sightings object, and sends it out to the list within a STIX Request object (see my other thread
J) asking if anyone else has seen this before.
·
Org B sees the STIX Request, interrogates it’s TI database, and finds that it’s analysts saw the same _javascript_ in HTML
from oddsite.com. They have worked out it was Threat Actor B behind it, as part of Campaign B.
·
Org B sends a STIX Response back to Org A containing the objects related to the oddsite.com and a new top-level relationship
object linking the Org A sightings object with the Org B data provided.
·
Org A now knows exactly what the _javascript_ on weirdsite.com is trying to do, what campaign it was part of, and who is behind
it. All without having an Indicator.
Removing the forced linkage between Sightings and Indicators gives us the freedom to use STIX in the way that Incident Responders operate
when Hunting. We see something odd, ask around to see if anyone else has seen it and worked out what it was, and then use that information to continue our investigations. We need Indicators and Sightings to be independent to allow that to occur.
Cheers
Terry MacDonald
Senior STIX Subject Matter Expert
SOLTRA | An FS-ISAC and DTCC Company
+61 (407) 203 206 |
terry@soltra.com
From: cti-stix@lists.oasis-open.org [mailto:cti-stix@lists.oasis-open.org]
On Behalf Of Barnum, Sean D.
Sent: Thursday, 29 October 2015 8:22 AM
To: Cory Casanave <cory-c@modeldriven.com>; Jason Keirstead <Jason.Keirstead@ca.ibm.com>; Jordan, Bret <bret.jordan@bluecoat.com>
Cc: Thompson, Dean <Dean.Thompson@anz.com>; Terry MacDonald <terry@soltra.com>; cti-stix@lists.oasis-open.org
Subject: Re: [cti-stix] Top-level Sighting Object from last meeting
Observing something “ad hoc” is simply an observation and is currently expressed using Observable.
A Sighting is saying that something was observed that has been identified as of potential interest by an Indicator. Kind of like a police APB.
Must a sighting have an indicator or can you observe something “ad hoc”?
Agree 100% and I think this also nerds to be considered as we decide what is "mandatory" and what isn't in the sighting.
We are looking at potentially having to feed tens of millions of sightings a day to one system in some
MSSP situations. They have to be as small and compact as possible. Ideally, just an ID and as little superfluous info as possible alongside it.
Sent from IBM Verse
Jordan, Bret --- Re: [cti-stix] Top-level Sighting Object from last meeting ---
I think the vast majority of sightings will be more or less auto generated. There may be a need to support sightings of other higher level objects, but the quantity or volume of those will be really
small in relative terms.
Bret Jordan CISSP
Director of Security Architecture and Standards | Office of the CTO
PGP Fingerprint: 63B4 FC53 680A 6B7D 1447 F2C0 74F8 ACAE 7415 0050
"Without cryptography vihv vivc ce xhrnrw, however, the only thing that can not be unscrambled is an egg."
Does this depend on what is producing the sighting object ?, for example the first option appeals to me because from an ability to auto-script and
generate it could be potentially easy to make those links of observations to a sighting object. With regards to “Threat Actor’s” and “TTP’s”, doesn’t it get a little hard because (based on the experience I have had), you have more softer definitions you place
into those top level objects, they are not straight out IP addresses, MD5’s or email addresses.
Do others seeing the sighting object as being a construct which would more times than not be something that is auto-generated by various systems,
rather than a construct put together manually which include thought and analysis ? (that’s not to say that you couldn’t do that, just that it is a lot harder).
Personally, I prefer option 1.
One other thing I wanted to highlight was a point raised by Aharon late last week in the STIX meeting. We need to discuss what exactly we want the Sighting Object
to be able to reference. As I understand it the available options are:
· Should
a Sighting Object only reference ‘detected’ information (e.g. Observable Instances only – most similar to an Indicator)
· Should
a Sighting Object reference any other top-level Object (e.g. Threat Actor’s, TTPs, etc). This will be the most flexible and least restrictive for the future.
· Should
a Sighting Object reference some top-level Objects based on STIX model (e.g. Threat Actor’s, TTPs, Indicators, Incident, Report)
My personal preference is for the first option – but I am very interested
in what others think. I think we need to scope the Sighting object and discuss its purpose fairly early on to work out exactly where it will fit in the model.
Senior STIX Subject Matter Expert
SOLTRA | An FS-ISAC and DTCC Company
- What is "Alternative_ID" ?
The Alternative_ID was taken from the IndicatorType object. From that object’s description it ‘Specifies an alternative identifier (or alias) for the cyber threat
Indicator.’. The idea was to allow the Sighting to have a reference of some kind, referring back to the ID that the tool that identified it had given it. It may not be useful in the Sighting context but I wanted to include it just in case. TBH we may want
to think more about how we handle ‘aliases’ in general across the whole STIX model…
- Can you add to the proposal, which fields would be mandatory, and which optional? It's unclear to me. I presume a subset is mandatory, but not all.
Yes, my thinking was that a subset of the Sighting fields would be mandatory. I’ve suggested some below but would really like to see what everyone else thinks.
Suggested Mandatory Fields
· Timestamp
/ Time Period
· One
or more referenced objects (i.e. idref) – (This would be done via Top-level relationship object)
Suggested Optional Fields
· Timestamp
/ Time Period
· Victim
Organization information
· Producer
Organization information
· Alternative
Sighting ID
Mark’s other post earlier today reminded me that I had earlier requested a Sighting object last year (https://github.com/STIXProject/schemas/issues/306).
In there I even drew a nice updated STIX model diagram to include where I personally saw the Sighting object located (thanks to Bret for the visio). But this may help provide more context?
Please note this reflects my own personal viewpoint.
Senior STIX Subject Matter Expert
SOLTRA | An FS-ISAC and DTCC Company
- What is "Alternative_ID" ?
- Can you add to the proposal, which fields would be mandatory, and which optional? It's unclear to me. I presume a subset is mandatory, but not all.
Hi All,
Given the flurry of discussions about features for STIX v2.0, it’s probably the right time to resend the
top-level STIX Sighting Object conversation starter out again. So here are the slides. Please feel free to comment/feedback/complain/call me names.
Please note – the strawman UML model is an abstraction based on the use of the Sighting Object only for
Observable Instances; it assumes that Indicators will similarly be restricted to only allowing Observable Patterns. The idea being that Indicators = ‘things to look for’ and Sightings = ‘things we’ve found’.
Cheers
Terry MacDonald
Senior STIX Subject Matter Expert
SOLTRA | An FS-ISAC
and DTCC Company
+61 (407) 203 206 | terry@soltra.com
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