I think this is just me not understanding where the COA minigroup is headed, not that what you put together is confusing.
Anyway, when you say “the COA should apply to the host identified by the sighting” do you mean:
This is a COA that was
actually taken and the producer is telling others about that
This is a COA that
could be taken and the producer is telling the owner of the host either as a recommendation or a command
The Damballa report had both (talked about what they did, and had some recommendations for what others could do).
On your latter scenario, I’d have the same question...are you recommending the COA, directing it as part of like an orchestration capability, or reporting on it? I think the answer might be different in the
different scenarios. Separately, I don’t think Identity really captures the concept of a “host”. Identity is really an organization or an individual, STIX deferred having an “asset” SDO to capture the concept of a host.
John
From: "Jyoti Verma (jyoverma)" <>
Date: Thursday, September 14, 2017 at 6:12 PM
To: John Wunder <>, "" <>
Subject: Re: [cti-stix] Draft Threat model for IMDDOS COAs
Hi John,
I cooked this up late last night and there is no particular reason for calling it ‘applies-to’ vs. anything else. The idea was that the COA should apply to the host identified by the sighting. In the example
shown here the COAs are atomic (delete registry key, block the process that is reaching out to the C2 domains, block the process that is reaching out to the TLD domain) and there is a higher level COA (IMDDOS malware removal) that is using these atomic COAs
(I called this relationship parent-of for lack of a better term).
We discussed this example during the mini group call today and will be updating the model for a more real use case – ie. When a sighting is made, the identified host needs to be quarantined and then a series
of steps to remove the malware need to be done. This can be captured by 2 COAs – “Quarantine host” and “Malware cleanup”. What I’m struggling with is if these COAs should be related to the Sighting or directly to the Identity (identified host). Thoughts?
Thanks,
Jyoti
Technical Leader,
CTO office Security Business Group,
Cisco Systems Inc.
From: "Wunder, John A." <>
Date: Thursday, September 14, 2017 at 12:40 PM
To: Jyoti Verma <>, "" <>
Subject: Re: [cti-stix] Draft Threat model for IMDDOS COAs
Hey Jyoti,
This is super comprehensive, thanks! I had a question for you…right now you have COA tied to Sightings as “applies-to”. What data does that indicate? That the COA was actually applied to the case described
in that sighting, or that it COULD apply? We’ve done some explorations of that concept and I was curious what you were thinking.
John
From: <> on behalf of "Jyoti Verma (jyoverma)" <>
Date: Thursday, September 14, 2017 at 5:27 AM
To: "" <>
Subject: [cti-stix] Draft Threat model for IMDDOS COAs
Hi,
Based on the discussions in the COA mini group, I extended Rich’s threat model for IMDDOS with some COAs and relationships. We can work through this in the COA mini group call later today.
Thanks,
Jyoti
Technical Leader,
CTO office Security Business Group,
Cisco Systems Inc.
