WPAD Service Exploit

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Identifies probable exploitation of the Web Proxy Auto-Discovery Protocol (WPAD) service. Attackers who have access to the local network or upstream DNS traffic can inject malicious JavaScript to the WPAD service which can lead to a full system compromise.

Rule type: eql

Rule indices:

  • logs-endpoint.events.*

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: 100

References: None

Tags:

  • Domain: Endpoint
  • OS: Windows
  • Use Case: Threat Detection
  • Tactic: Privilege Escalation

Version: 1

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

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/* preference would be to use user.sid rather than domain+name, once it is available in ECS + datasources */
/* didn't trigger successfully during testing */

sequence with maxspan=5s
  [process where host.os.type == "windows" and event.type == "start" and process.name : "svchost.exe" and
     user.domain : "NT AUTHORITY" and user.name : "LOCAL SERVICE"] by process.entity_id
  [network where host.os.type == "windows" and network.protocol : "dns" and process.name : "svchost.exe" and
     dns.question.name : "wpad" and process.name : "svchost.exe"] by process.entity_id
  [network where host.os.type == "windows" and process.name : "svchost.exe"
     and network.direction : ("outgoing", "egress") and destination.port == 80] by process.entity_id
  [library where host.os.type == "windows" and event.type : "start" and process.name : "svchost.exe" and
     dll.name : "jscript.dll" and process.name : "svchost.exe"] by process.entity_id
  [process where host.os.type == "windows" and event.type == "start" and
     process.parent.name : "svchost.exe"] by process.parent.entity_id

Framework: MITRE ATT&CKTM