Internet DRAFT - draft-jordan-cacao-introduction
draft-jordan-cacao-introduction
IETF B. Jordan
Internet-Draft Symantec Corporation
Intended status: Informational A. Thomson
Expires: September 9, 2019 LookingGlass Cyber
J. Verma
Cisco Systems
March 08, 2019
Collaborative Automated Course of Action Operations (CACAO) for Cyber
Security
draft-jordan-cacao-introduction-01
Abstract
This document describes the need for defining a standardized language
and associated protocols to capture and automate a collection of
coordinated cyber security actions and responses. This collection of
actions is called a Course of Action (COA) Playbook.
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on September 9, 2019.
Copyright Notice
Copyright (c) 2019 IETF Trust and the persons identified as the
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described in the Simplified BSD License.
Table of Contents
1. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 9
5. Architecture . . . . . . . . . . . . . . . . . . . . . . . . 11
6. Deliverables . . . . . . . . . . . . . . . . . . . . . . . . 12
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
8. Security Considerations . . . . . . . . . . . . . . . . . . . 12
9. Privacy Considerations . . . . . . . . . . . . . . . . . . . 13
Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14
1. Definitions
System: A system is an heterogeneous set of any IT capabilities
including hardware, software, endpoints (including IoT), networks,
data centers and platforms with no assumptions on deployment form
factor (physical, virtual, microservices), deployment scenario,
geographic distribution, or dispersion.
COA: A Course of Action is a manual or automated action applicable to
a given system or human process.
COA Playbook: A COA Playbook is the instantiation of a sequence of
COAs that can be executed on a system or set of systems to protect it
against Cyber threats and attacks.
COA Playbook Template: A set of high level COA actions defined by an
organization on how they might respond generically to a specific
threat scenario without the specific details of the threat included.
Example: high level steps for mitigating or remediating malware in
general.
CACAO: A Collaborative Automated Course of Action Operation
represents a COA Playbook that can be coordinated and deployed with
verified responses across a set of heterogeneous cyber security
systems.
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2. Introduction
To defend against threat actors and their tactics, techniques, and
procedures, organizations need to identify, create, and document
prevention, mitigation, and remediation steps. These steps when
grouped together into a course of action (COA) Playbook are used to
protect systems, networks, data, and users. The problem is, once
these steps have been created there is no standardized and structured
way to document them, verify they were correctly executed, or easily
share them across organizational boundaries and technology stacks.
A COA Playbook with automated steps would enable system and network
operators to respond to incidents in machine relevant time.
While some attacks may be well known to certain security experts and
cyber researchers they are often not documented in a way that would
enable automated mitigation or remediation. A documented way of
describing prevention, mitigation, and remediation actions is
critical for cyber defenders to respond more quickly and reduce the
exposure from an attack.
In a similar manner, this will allow organizations to prevalidate the
course of actions and potentially simulate the course of actions and
understand their implications in terms of potential overall cost,
revenue loss, user experience, risk of churn, risks in general, and
liabilities. Indeed certain COAs might lead to radical mitigations
in the system which might lead to more or less acceptable collateral
damages to answer a certain cyber threat. Like at war, 'officers'
responsible to engage or trigger the execution of a COA could be
offered a chance to understand their options first in selecting the
most appropriate COA.
While many attempts have been made over the years in the IETF and
other SDOs to address certain elements of this problem space, there
is currently no consolidated and standardized language or means that
would allow cyber actions to be automatically coordinated, sequenced,
processed and shared to enable cyber defenders to respond in machine
relevant time. Some efforts such as BPMN have traditionally focused
on higher-level non-cyber constructs for process definition, and
other efforts like OpenC2 have focused purely on atomic actions, but
none have focused on the overlay processes required for this to be
used in a broader cyber security response use case.
To enable and assist cyber defense, a solution needs to be created to
securely document, share, and automate the actions needed to prevent,
mitigate, and remediate threats. This effort will focus on providing
an information model, data serialization, and transport for defining,
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sharing, and processing Collaborative Automated Course of Action
Operations (CACAO).
Every COA Playbook will consist of a sequence of cyber defense
actions that can be coordinated and deployed with verified responses
across a set of heterogeneous cyber security systems. The primary
focus will be on the definition of the higher level sequence of
actions (perhaps a tree or graph) and where possible we will leverage
existing efforts that _may_ define the atomic actions to be included
in a process or sequence.
A key use of CACAO is to enable more senior cyber defenders to
document and share detailed step by step actions and solutions for a
given threat that can be deployed en mass across heterogenous system
and network solutions. It also enables less experienced or junior
personnel to have greater confidence in their efforts to defend their
networks based on shared COA Playbooks defined by other organizations
and other experts in the field of cyber security. These suggested
steps, that may be executed automatically, provided by the senior
personnel can also help guide the junior personnel in the correct
ways to handle a variety of the security response without requiring
senior personnel being involved.
This effort is intended to define a way for chaining atomic security
actions together. The atomic actions themselves could be formed from
a variety of languages such as STIX COA; OpenC2; Cisco IOS; Juniper
JunOS....etc.
This effort will primarily focus on defining a semantic
representation and information model to allow the construction of a
COA Playbook. Our secondary focus will be on defining a
serialization and transport protocol to enable COA Playbooks to be
used between systems.
3. Examples
The following 2 simplified examples explain CACAOs that are written
in pseudo programmatic terms to explain how the COA Playbook contains
both human and machine defined actions that are executed in response
to a threat. For each COA Playbook, the initial trigger event is
defined and then followed by a set of COAs that can be sequential,
conditional-based-flow, or a combination of both.
Example 1: Infected Host Mitigation COA Playbook This example defines
the COA Playbook for an organization to respond to threat detection
on a host within their internal network after a specific type of
threat has been detected on the host. The playbook defines both
machine and human steps to describe the mitigation response.
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BEGIN-PLAYBOOK
Playbook-Name: InfectedHostMitigation1
Playbook-Trigger-Event:
o Indicator indicator-8e2e2d2b-17d4-4cbf-938f-98ee46b3cd3f defines a
command and control server based on CIDR 192.0.2.x that has been
communicated to and from the host 198.51.100.12.
o A trigger event may be defined in STIX2
o A trigger defines an entry point into the playbook steps as
follows.
BEGIN-COAs
COA:
o Id: 1
o Type: Human
* Question: Ask the user whether they wish to review the
mitigation procedures before proceeding?
* Answer-Y-or-N
+ If Y: Proceed to Id: 2
+ If N: Proceed to Id: 3
COA:
o Id: 2
o Type: Human
* Operation: Display mitigation procedures.
COA:
o Id:3
o Type: Machine
* Operation: Vlan-Move
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* Variable: "HostVLANID ="infected-host.vlan
* Target: $$infected-host
* Destination: Quarantine VLAN ID
COA:
o Id:4
o Type: Machine
* Operation: Host-Image
* Target: $$infected-host
* ImageName: Windows-Good-Image1
COA:
o Id:5
o Type: Machine
* Operation: Vlan-Move
* Target: $$infected-host
* Destination: $$HostVLANID
END-COAs
END-PLAYBOOK
Example 2: Find and Remove Malware COA Playbook This example
describes a COA Playbook for an organization to find malware and then
if found to remove the malware from an infected host. The playbook
defines a more complicated sequence of machine instructions as
identified by the MACHINE-SEQUENCE operation in COA-Id{4}.
BEGIN-PLAYBOOK
Playbook-Name: FindRemoveMalware1
Playbook-Trigger-Event:
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o Indicator indicator-8e2e2d2b-17d4-4cbf-938f-98ee46b3cd3f defines a
malware hash $$inserthash that is known to identify a specific
malware file if found on a host system
o A trigger event may be defined in STIX2
o A trigger defines an entry point into the playbook steps as
follows.
BEGIN-COAs
COA:
o Id: 1
o Type: Human
* Question: Ask the user whether they wish to review the
mitigation procedures before proceeding?
* Answer-Y-or-N
+ If Y: Proceed to Id: 2
+ If N: Proceed to Id: 3
COA:
o Id: 2
o Type: Human
* Operation: Display mitigation procedures.
COA:
o Id:3
o Type: Machine
* Operation: Vlan-Move
* Variable: "HostVLANID ="infected-host.vlan
* Target: $$infected-host
* Destination: Quarantine VLAN ID
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COA:
o Id:4
o Type: Machine-Sequence {
* Delete run at start reg keys and triggers
* Reboot into SafeMode
* Kill process 3 then 1 then 2
* Delete temp files
* Delete compromised files from the system
* Delete other Reg keys
* Reboot system in to safe mode
* Verify processes do not restart
* Patch AV system
* Run updated AV scan
* Patch OS
* Run additional on-demand special AV scanners
* Reboot system to normal mode }
* Target: $$infected-host
COA:
o Id:5
o Type: Machine
* Operation: Vlan-Move
* Target: $$infected-host
* Destination: $$HostVLANID
END-COAs
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END-PLAYBOOK
4. Requirements
Below is a list of high level requirements that this effort needs to
address.
o Multiple Actions: The solution needs to support the ability to
describe one or more actions that can be processed in a batch
manner or as-a-group.
o Data Protection, Integrity and Authentication (Rules for data in
motion and at rest): All requests and responses must be
confidential and therefore a secure protocol should be used to
convey these messages such as TLS (but not limited to). The COA
Playbooks and actions must be able to be encrypted (and optionally
signed) to ensure integrity and that they are only accessible by
authenticated and authorized users.
o Globally Unique Identifiers: All transactions (requests,
responses, and notifications) need to be able to be tracked,
monitored, and recorded for security and operational reasons,
including the ability to backout failed actions. This means
responses and notifications need a way to be tied back to the
original request. Globally unique identifiers apply to both the
COA Playbook and the COAs within the playbook. All transactions
tracked, monitored and recorded will be restricted to the same
management zone as the systems initiating the transactions and
operating on the results. All systems operating in that
management zone will support a common and agreed set of privacy
associated with those transactions such that no concerns over loss
of privacy or unexpected data exposure occurs.
o Reporting: Provide the ability to gather single and batch reports
of events for responses. All report events must have a timestamp,
identifier of original request or rule causing event, and option
for a full dump of matching data (network, endpoint config....etc)
to be included in the event record. The report could be either
synchronously requested or be an asynchronous event (syslog) with
periodic updates.
o Sequences of Atomic Actions: The ability to define an ordered list
of atomic actions that must be executed as a combined set rather
than as a sequence.
o Projects & Project Templates: These should support actions for
machine automation, human actions / intervention, and high level
conceptual actions.
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o Customization: Provide the option to include custom actions in a
batch or set of atomic actions.
o Conditional Logic: This solution needs the ability to include
action sequences that can support conditional logic, logical and
comparative operators, and behavioral logic.
o Project Testing: Ability to support what-if deployments where a
defined COA Playbooks can be verified before deploying to a real
system or environment, and perhaps be able to identify all the
organizations that have tested it and verified it.
o Auditability: The solution needs the ability to provide full
confirmation (tracking and logging) of each COA at every
transaction state.
o Digital Signature Chain / Attribution with Identified Signed
Topic: The solution needs the ability to track multiple digital
signatures to show a chain of trust where it identifies the
specific Signed Topic that is being signed. This solution should
also support multiple independent organizations signing and
verifying the correctness, accuracy, and validity of the COA
Playbook or individual COA where the Signed Topic being signed by
that independent entity is specified.
o Input: One or more technical indicators, prioritization
indicators, and rule names (optional).
o Transport Methods: This solution needs to support the ability for
clients to send COAs directly to an end device (request/response)
and also to a communications channel (publish/subscribe).
o Versioning: The solution needs to support both incremental
versioning and semantic versioning, along with assertions that the
COA works with certain products. This will enable support of
multiple versions of a COA across products so that not all systems
are required to be the same version to implement COA Playbooks.
Newer COA Playbooks will provide information that allows consumers
to relate the new version to prior versions.
o Transactions: Needs the ability for systems to have the option to
support both atomic and non-atomic transactions.
o System Targeting: The solution needs the ability to identify the
type, version, patch level of one or more systems that this COA is
applicable for.
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o Project Versioning: Need ability to version (and track) COA
Playbooks and Templates
o Data Markings: Need ability to support data marking at a COA
Playbook level such as the Traffic Light Protocol (TLP) for the
project.
o Command and Control Management Separation (Definition vs Execution
Environment): A COA Playbook (and the contained atomic COAs) may
be defined in one system by one or more authors, but the COA
Playbook may be executed in an operational environment where the
systems and users of those systems have different authentication
and authorizations for the COA. In order for the COA Playbook to
execute correctly it must have authorization in the operational
environment where it is executed. Therefore the credentials of
the authors should not be relied upon to execute correctly in the
execution environment. Also, the security environment executing
the COA Playbook will likely be different from where the COA
Playbook was defined.
o Integration: Ensure that COA Playbooks can be used in and work
with existing threat intelligence data models, for example STIX.
o Flexibility: Allow the COA PLaybook to benefit and leverage
existing capabilities available in 'the system' such as atomic
ways to exchange security commands 'a la openc2', or read from
available security capabilities in a standard way 'a la i2nsf' to
understand what it can actually do or to allow conditional COA
sequences
5. Architecture
A Collaborative Course of Action workflow will consist of several
components, including at least:
+----------+ +----------+ +----------+ +----------+
| Define | --> | Verify | --> | Deliver | --> | Execute |
| COA | <-- | COA | | COA | | COA |
| Playbook | | Playbook | | Playbook | | Playbook |
+----------+ +----------+ +----------+ +----------+
^ ^ ^ ^
| | | |
| +--------------------------+ |
<-------- | Monitoring and Reporting | -------->
+--------------------------+
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o Define: Where a COA Playbook is defined based on various inputs
both automated and manually derived.
o Verify: Where a COA Playbook is reviewed for accuracy,
correctness, and is properly defined to execute correctly in a
target environment without making any changes to the target
environment.
o Deliver: Where a COA Playbook is distributed to the systems that
will execute the COA Playbook. Distribution includes checking
that the COA Playbook has been deployed correctly and has followed
the rules defined within the project for atomic transactions.
o Execute: Where a COA Playbook is evaluated by one or more security
infrastructure systems and execution events are communicated to
the COA Playbook monitoring step. It can run either in full
execution or in verification mode.
o Monitoring: Where a COA Playbook execution is monitored and
metrics are determined on the COA Playbook to enable further
refinement or improvement to the COA Playbook definition.
6. Deliverables
This effort will need to produce and deliver the following documents:
1. An overview and architecture document
2. A COA Playbook data model in JSON / CBOR
3. Define how COA Playbooks will be distributed between each system
within the process including leveraging existing transport
mechanisms and any new APIs/Protocols required.
7. IANA Considerations
This memo includes no request to IANA.
8. Security Considerations
The solution described by this document provides a mechanism to
define a series of actions that can be applied to a network or host
system to prevent, mitigate, or remediate some threat. Discussion is
needed about how to protect such a mechanism and the information it
is managing from unauthorized access or disclosure.
In a principle of "who guards the guards" ("quis custodiet Ipsos
custodes" Juvenal, Satire VI, lines 347-348) it is essential to armor
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the COA service against itself and to consider a COA-SELF project for
consistency and coherency where the target system of the COA is the
COA service itself.
A breach in the COA service would break the integrity of an entire
target system, potentially at extra large scale.
9. Privacy Considerations
Discussion is also needed about privacy considerations around how the
endpoint devices and systems are identified and to ensure that any
commands are encoded in a safe way and if the COA Playbook needs to
collect private data it is still compliant to privacy regulations and
offers all the mechanisms to guarantee compliance to such frameworks
such as auditability, security, encryption, right to be forgotten,
consents, etc.
Contributors
o Allen Hadden
IBM
ahadden@us.ibm.com
o David Waltermire
NIST
david.waltermire@nist.gov
o Efrain Ortiz
Symantec
efrain_ortiz@symantec.com
o Jason Keirstead
IBM
jason.keirstead@ca.ibm.com
o Jason Webb
LookingGlass Cyber
jwebb@lookingglasscyber.com
o Kyle Mackenzie
JPMC
Mackenzie.kyle@jpmorgan.com
o Subodh Kumar
JPMC
subodh.kumar@jpmorgan.com
o Swaroop Pradhan
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JPMC
swaroop.s.pradhan@jpmorgan.com
o Vivek Jain
JPMC
vivek.jain@jpmchase.com
Authors' Addresses
Bret Jordan
Symantec Corporation
350 Ellis Street
Mountain View CA 94043
USA
Email: bret_jordan@symantec.com
Allan Thomson
LookingGlass Cyber
10740 Parkridge Blvd, Suite 200
Reston VA 20191
USA
Email: athomson@lookingglasscyber.com
Jyoti Verma
Cisco Systems
170 West Tasman Dr.
San Jose CA 95134
USA
Email: jyoverma@cisco.com
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