# Excessive denied SMB traffic

**URL:** <https://discuss.elastic.co/t/excessive-denied-smb-traffic/323184>\
**Category:** SIEM\
**Tags:** detection-rules\
**Created:** [January 14, 2023, 7:16pm UTC](https://discuss.elastic.co/t/excessive-denied-smb-traffic/323184 "2023-01-14T19:16:02Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Abulfaz](https://avatars.discourse-cdn.com/v4/letter/a/aca169/32.png) [@Abulfaz](https://discuss.elastic.co/u/Abulfaz)\
**Post date:** [January 14, 2023, 7:16pm UTC](https://discuss.elastic.co/t/excessive-denied-smb-traffic/323184/1 "2023-01-14T19:16:02Z")

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How should I write Elastic rule that detect if excessive denied SMB traffic from a single host?

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**Author:** ![justin\_ibarra](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/justin_ibarra/32/110828_2.png) [@justin\_ibarra](https://discuss.elastic.co/u/justin_ibarra)\
**Post date:** [January 18, 2023, 12:00am UTC](https://discuss.elastic.co/t/excessive-denied-smb-traffic/323184/2 "2023-01-18T00:00:55Z")

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Hello there 👋,

It is dependent on the data source you are using, but I assume you may be referring to firewall logs due to "denying".

The easiest way would be to use a [threshold rule](https://www.elastic.co/guide/en/security/current/rules-ui-create.html#create-threshold-rule) similar to the following:

 ![image](https://us1.discourse-cdn.com/elastic/original/3X/6/c/6cdae0fb3e3298690dedeb89e259ab72c447600a.png).

There are other options as well that may make sense, depending on the data and expectations. The best way to discuss these are directly within our [detection-rules repo](https://github.com/elastic/detection-rules). If you open an issue, you can collaborate with the team to come up with a solution (and possibly merge into production).

We also have several [existing rules](https://github.com/search?q=repo%3Aelastic%2Fdetection-rules+smb+language%3ATOML+path%3A%2F%5Erules%5C%2F%2F&type=code&l=rules%2F) which target SMB traffic in various ways.

Hope this helps!

Justin

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**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [February 15, 2023, 12:01am UTC](https://discuss.elastic.co/t/excessive-denied-smb-traffic/323184/3 "2023-02-15T00:01:36Z")

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