Suspicious Execution - Short Program Name

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Identifies process execution with a single character process name. This is often done by adversaries while staging or executing temporary utilities.

Rule type: eql

Rule indices:

  • winlogbeat-*
  • logs-endpoint.events.*
  • logs-windows.*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References: None

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Defense Evasion

Version: 7

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guide

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## Setup

If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.

Rule query

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process where event.type in ("start", "process_started") and length(process.name) > 0 and
 length(process.name) == 5 and host.os.name == "Windows" and length(process.pe.original_file_name) > 5

Framework: MITRE ATT&CKTM