diff --git a/best-practices-in-threat-intelligence.html b/best-practices-in-threat-intelligence.html index b0dd514..073c3ed 100644 --- a/best-practices-in-threat-intelligence.html +++ b/best-practices-in-threat-intelligence.html @@ -468,7 +468,7 @@ body.book #toc,body.book #preamble,body.book h1.sect0,body.book .sect1>h2{page-b

Whilst this book can be used as a general guide, it is based on the open source threat intelligence platform called MISP to give the reader the most practical and real-world experience.

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The best practices described herein are from Information Sharing communities (ISAC or CSIRT) which are regularly using MISP to support their work and sharing practices.

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The best practices described herein are from Information Sharing communities (ISAC or CSIRT) which are regularly using MISP to support their work and sharing practices.

@@ -513,7 +513,7 @@ One of the main questions to ask is:

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In the 1st case, MISP includes a mechanism to propose changes to the original creator, a mechanism MISP refers to as proposals. By using proposals, you can propose a change to the value or the context of an attribute (such as a typographic error in an IP address, missing contextual information, type of the information, the category or the removal of an IDS flag). The proposal will be sent back to the original author who can decide to accept or discard it.

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In the 1st case, MISP includes a mechanism to propose changes to the original creator, a mechanism MISP refers to as proposals. By using proposals, you can propose a change to the value or the context of an attribute (such as a typographic error in an IP address, missing contextual information, type of the information, the category or the removal of an IDS flag). The proposal will be sent back to the original author who can decide to accept or discard it.

The advantages of using the proposal system include the lack of a need to create a new event as well as the process itself being very simple and fast. However, it assumes that the party providing the improvements is willing to lose control over the proposed data. This is pretty efficient for small changes but for more comprehensive changes, especially those that include non-attribute information such as galaxy clusters or objects, the event extension is more appropriate.

@@ -536,7 +536,7 @@ For more information about the extended event functionality in MISP, the blog po

In the 3rd scenario your use-case might be highly automated, e.g. scripted processing of events and attributes via PyMISP and the end-consumer is mainly another automated process, e.g. Intrusion Detection System, 3rd part visualization tool etc. This, for automagic reasons, becomes exponentially unreliable. -What is primal in this case is to fully understand what the IDS flag in MISP does and how it impacts attributes. +What is primal in this case is to fully understand what the IDS flag in MISP does and how it impacts attributes. Further on, it is even more important to fully understand the entire tool-chain, cradle-to-grave style. Where does the data come from (cradle) where does it go to (grave) and what processes "touch" the data as it flows through, small diagrams can help tremendously to visualize the actual data-flow. Those diagrams will mostly be of use once unexpected results occur, or other errors appear somewhere in the chain.

@@ -614,7 +614,7 @@ When asking for the support of the community, using a specific taxonomy such as

Intelligence Tagging

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There are several factors to successful and efficient intelligence sharing. Certainly, one major aspect is the quality of the indicators (or observable depending on the definition you use), +

There are several factors to successful and efficient intelligence sharing. Certainly, one major aspect is the quality of the indicators (or observable depending on the definition you use), stored as attributes within a MISP event itself. However, it does not stop there. Even the most viable information gained by a shared event can render itself complete useless if not classified and tagged accordingly. One feature which enables a uniformed classification is implemented in MISP as tags. Currently, there are two types of tags, which differ in the respective place they are set.

@@ -660,14 +660,14 @@ In future releases there will also be tagging for MISP Objects. Which is, someho -MISP Objects in its plain concept is a grouping of indicators within one event. These grouped indicators are somehow logically linked together. The specific relationship is described by the individual object type. +MISP Objects in its plain concept is a grouping of indicators within one event. These grouped indicators are somehow logically linked together. The specific relationship is described by the individual object type. A simple file object, links for example a filename to its observed hash values (md5, sha1, sha256 and many more). This can further be enriched via misp-modules or other plug-ins.
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A frequent use-case for placing additional tags on attribute level would be to lower the confidence in certain attributes. If the event is classified with a high confidence tag, some indicators e.g. legit-but-compromised domains or popular filenames should be labeled with a lowered confidence class. There are several real world examples where this or similar attribute specific tagging has proven to be worthwhile.

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A frequent use-case for placing additional tags on attribute level would be to lower the confidence in certain attributes. If the event is classified with a high confidence tag, some indicators e.g. legit-but-compromised domains or popular filenames should be labeled with a lowered confidence class. There are several real world examples where this or similar attribute specific tagging has proven to be worthwhile.

Most of the tags are organised in dedicated MISP Taxonomies. Those schema dictate how tags should look like and how they are to be applied in certain conditions. @@ -706,7 +706,7 @@ This data must not leave the boundaries of this virtual border of the recipient -One mitigation the scenario of mis-classified data, would be to use the warning lists (or notice lists) as a canary. Whilst not ideal and far from a defacto solution to catch all issues, it would be a good-enough-yet-coarse way of detection. +One mitigation the scenario of mis-classified data, would be to use the MISP warninglists (or MISP noticelists) as a canary. Whilst not ideal and far from a defacto solution to catch all issues, it would be a good-enough-yet-coarse way of detection. @@ -762,18 +762,13 @@ Expressing the confidence or the lack of it in an analysis is a critical step to

Analysis or reports are often shared together with technical details, but often lack the associated overall confidence level. -To ascertain this confidence level you can use for example the MISP Taxonomies called admiralty-scale and/or estimative-language. +To ascertain this confidence level you can use for example the MISP MISP Taxonomies called admiralty-scale and/or estimative-language. This is a very human way to describe either globally an event or individual indicators of an event, with a set of easy to read human tags. (e.g: admiralty-scale:source-reliability="a/b/c…​", estimative-language:likelihood-probability="almost-no-chance", estimative-language:confidence-in-analytic-judgment="moderate") Generally it is good practice to do this globally for the event as this will enrich the trust/value if set. Using this in an automated way is also possible but without human intervention, or AI that actually works, not recommended. Also, on events with hundreds of attributes this is cumbersome and perhaps unfeasible and will just frustrate operators. The obvious side-effect of this approach is that automation will be the overall benefactor too upping the trust on that level too.

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[TODO: revise description of estimative probability]
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Thus, adding confidence or estimative probability has multiple advantages such as:

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  • Depending on source organisation, have an affirmative that some HumInt has one into the sharing process

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    [TODO: define counter and competitive analyses]
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  • @@ -808,7 +798,7 @@ The obvious side-effect of this approach is that automation will be the overall -MISP taxonomies contain an exhaustive list of confidence levels including words of estimative probability or confidence in analytic judgment. +MISP Taxonomies contain an exhaustive list of confidence levels including words of estimative probability or confidence in analytic judgment. @@ -848,7 +838,7 @@ Having a workflow to follow, and be able to refer to, is something useful for th

    One of the possible methodologies is to use tags to mark the information and convey the current state of an analysis.

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    For instance the MISP Workflow Taxonomy allows the user to describe the state of an analysis, as complete or incomplete. Moreover, it can be used to clearly specify what still needs to be done using the todo tags. The workflow taxonomy is separated into two parts. One part is related to the actions to be done (todo) and the other part is about the current state of the analysis(state) such as incomplete, draft or complete.

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    For instance the MISP Workflow [Taxonomy] allows the user to describe the state of an analysis, as complete or incomplete. Moreover, it can be used to clearly specify what still needs to be done using the todo tags. The workflow taxonomy is separated into two parts. One part is related to the actions to be done (todo) and the other part is about the current state of the analysis(state) such as incomplete, draft or complete.

    @@ -879,16 +869,25 @@ Classifying information is something that has proven being very useful in lots o
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    The first tool we can use to classify information are tags and taxonomies -. Tags can be used to describe how the information can be shared, using the tlp (Traffic Light Protocol) taxonomy, in order to prevent information leaks. -. They can also be used to describe the source where information came from. -. Many taxonomies allow the user to further explain the kind of threat.[TODO: was that the meaning?] ---mapping--

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    The first tool we can use to classify information are tags and taxonomies

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      Tags can be used to describe how the information can be shared, using the tlp (Traffic Light Protocol) taxonomy, in order to prevent information leaks.

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      They can also be used to describe the source where information came from.

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      Many taxonomies allow the user to further explain the kind of threat.

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