Microsoft IIS Connection Strings Decryptionedit

Identifies use of aspnet_regiis to decrypt Microsoft IIS connection strings. An attacker with Microsoft IIS web server access via a webshell or alike can decrypt and dump any hardcoded connection strings, such as the MSSQL service account password using aspnet_regiis command.

Rule type: eql

Rule indices:

  • winlogbeat-*
  • logs-windows.*

Severity: high

Risk score: 73

Runs every: 5m

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

Maximum alerts per execution: 33



  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Credential Access

Version: 101

Rule authors:

  • Elastic

Rule license: Elastic License v2

Investigation guideedit

Rule queryedit

process where event.type == "start" and
  ( : "aspnet_regiis.exe" or == "aspnet_regiis.exe") and
  process.args : "connectionStrings" and process.args : "-pdf"