name: Linux At Application Execution
id: bf0a378e-5f3c-11ec-a6de-acde48001122
version: 2
date: '2022-05-26'
author: Teoderick Contreras, Splunk
type: Anomaly
datamodel:
- Endpoint
description: The following analytic identifies a suspicious process creation of At
  application. This process can be used by malware, adversaries and red teamers to
  create persistence entry to the targeted or compromised host with their malicious
  code. This anomaly detection can be a good indicator to investigate the event before
  and after this process execution, when it was executed and what schedule task it
  will execute.
search: '| tstats `security_content_summariesonly` count from datamodel=Endpoint.Processes
  where  Processes.process_name IN ("at", "atd") OR Processes.parent_process_name
  IN ("at", "atd") by Processes.dest Processes.user Processes.parent_process_name
  Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
  Processes.process_guid | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)` | `linux_at_application_execution_filter`'
how_to_implement: To successfully implement this search, you need to be ingesting
  logs with the process name, parent process, and command-line executions from your
  endpoints into the Endpoint datamodel. If you are using Sysmon, you can use the Add-on for Linux Sysmon from
  Splunkbase.
known_false_positives: Administrator or network operator can use this application
  for automation purposes. Please update the filter macros to remove false positives.
references:
- https://attack.mitre.org/techniques/T1053/001/
- https://www.linkedin.com/pulse/getting-attacker-ip-address-from-malicious-linux-job-craig-rowland/
tags:
  analytic_story:
  - Linux Privilege Escalation
  - Linux Persistence Techniques
  - Linux Living Off The Land
  automated_detection_testing: passed
  cis20:
  - CIS 3
  - CIS 5
  - CIS 16
  confidence: 30
  context:
  - Source:Endpoint
  - Stage:Privilege Escalation
  - Stage:Persistence
  dataset:
  - https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1053.002/at_execution/sysmon_linux.log
  impact: 30
  kill_chain_phases:
  - Exploitation
  message: At application was executed in $dest$
  mitre_attack_id:
  - T1053.002
  - T1053
  nist:
  - DE.CM
  observable:
  - name: dest
    type: Hostname
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - Processes.dest
  - Processes.user
  - Processes.parent_process_name
  - Processes.process_name
  - Processes.process
  - Processes.process_id
  - Processes.parent_process_id
  risk_score: 9
  security_domain: endpoint
  asset_type: Endpoint