name: Detect Spike in AWS API Activity
id: ada0f478-84a8-4641-a3f1-d32362d4bd55
version: 2
date: '2020-07-21'
author: David Dorsey, Splunk
type: batch
datamodel: []
description: This search will detect users creating spikes of API activity in your
  AWS environment.  It will also update the cache file that factors in the latest
  data. This search is deprecated and have been translated to use the latest Change
  Datamodel.
search: '`cloudtrail` eventType=AwsApiCall [search `cloudtrail` eventType=AwsApiCall
  | spath output=arn path=userIdentity.arn | stats count as apiCalls by arn | inputlookup
  api_call_by_user_baseline append=t | fields - latestCount | stats values(*) as *
  by arn | rename apiCalls as latestCount | eval newAvgApiCalls=avgApiCalls + (latestCount-avgApiCalls)/720
  | eval newStdevApiCalls=sqrt(((pow(stdevApiCalls, 2)*719 + (latestCount-newAvgApiCalls)*(latestCount-avgApiCalls))/720))
  | eval avgApiCalls=coalesce(newAvgApiCalls, avgApiCalls), stdevApiCalls=coalesce(newStdevApiCalls,
  stdevApiCalls), numDataPoints=if(isnull(latestCount), numDataPoints, numDataPoints+1)
  | table arn, latestCount, numDataPoints, avgApiCalls, stdevApiCalls | outputlookup
  api_call_by_user_baseline | eval dataPointThreshold = 15, deviationThreshold = 3
  | eval isSpike=if((latestCount > avgApiCalls+deviationThreshold*stdevApiCalls) AND
  numDataPoints > dataPointThreshold, 1, 0) | where isSpike=1 | rename arn as userIdentity.arn
  | table userIdentity.arn] | spath output=user userIdentity.arn | stats values(eventName)
  as eventName, count as numberOfApiCalls, dc(eventName) as uniqueApisCalled by user
  | `detect_spike_in_aws_api_activity_filter`'
how_to_implement: 'You must install the AWS App for Splunk (version 5.1.0 or later)
  and Splunk Add-on for AWS (version 4.4.0 or later), then configure your CloudTrail
  inputs. You can modify `dataPointThreshold` and `deviationThreshold` to better fit
  your environment. The `dataPointThreshold` variable is the minimum number of data
  points required to have a statistically significant amount of data to determine.
  The `deviationThreshold` variable is the number of standard deviations away from
  the mean that the value must be to be considered a spike.\

  This search produces fields (`eventName`,`numberOfApiCalls`,`uniqueApisCalled`)
  that are not yet supported by ES Incident Review and therefore cannot be viewed
  when a notable event is raised. These fields contribute additional context to the
  notable. To see the additional metadata, add the following fields, if not already
  present, to Incident Review - Event Attributes (Configure > Incident Management
  > Incident Review Settings > Add New Entry):\\n1. **Label:** AWS Event Name, **Field:**
  eventName\

  1. \

  1. **Label:** Number of API Calls, **Field:** numberOfApiCalls\

  1. \

  1. **Label:** Unique API Calls, **Field:** uniqueApisCalled\

  Detailed documentation on how to create a new field within Incident Review may be
  found here: `https://docs.splunk.com/Documentation/ES/5.3.0/Admin/Customizenotables#Add_a_field_to_the_notable_event_details`'
known_false_positives: ''
references: []
tags:
  analytic_story:
  - AWS User Monitoring
  asset_type: AWS Instance
  cis20:
  - CIS 16
  kill_chain_phases:
  - Actions on Objectives
  mitre_attack_id:
  - T1078.004
  nist:
  - DE.DP
  - DE.CM
  - PR.AC
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - eventType
  - userIdentity.arn
  risk_object: user
  risk_object_type: user
  risk_score: 10
  security_domain: network
