IMPORTANT: No additional bug fixes or documentation updates will be released for this version. For the latest information, see the current release documentation.
« Microsoft Build Engine Using an Alternate Name Microsoft IIS Service Account Password Dumped »
Elastic Docs ›Elastic Security Solution [7.11] ›Detections and Alerts ›Prebuilt rule reference

Microsoft IIS Connection Strings Decryption

edit

Microsoft IIS Connection Strings Decryption

edit

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-endpoint.events.*

Severity: high

Risk score: 73

Runs every: 5 minutes

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

Maximum alerts per execution: 33

References:

Tags:

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

Version: 3 (version history)

Added (Elastic Stack release): 7.10.0

Last modified (Elastic Stack release): 7.11.2

Rule authors: Elastic

Rule license: Elastic License

Rule query

edit
process where event.type in ("start", "process_started") and
(process.name : "aspnet_regiis.exe" or process.pe.original_file_name
== "aspnet_regiis.exe") and process.args : "connectionStrings" and
process.args : "-pdf"

Threat mapping

edit

Framework: MITRE ATT&CKTM

Rule version history

edit
Version 3 (7.11.2 release)
  • Formatting only
Version 2 (7.11.0 release)

  • Updated query, changed from:

    event.category:process and event.type:(start or process_started) and
(process.name:aspnet_regiis.exe or
process.pe.original_file_name:aspnet_regiis.exe or
winlog.event_data.OriginalFileName:aspnet_regiis.exe) and
process.args:(connectionStrings and "-pdf")
« Microsoft Build Engine Using an Alternate Name Microsoft IIS Service Account Password Dumped »