Exploiting CVE-2019-1388

Status: stable
Severity: critical
Log source: category process_creation, product windows
Author: Florian Roth (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects an exploitation attempt in which the UAC consent dialogue is used to invoke an Internet Explorer process running as LOCAL_SYSTEM

MITRE ATT&CK coverage

Tactic	Techniques
Privilege Escalation	`T1068` Exploitation for Privilege Escalation

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 1: Process creation
Security-Auditing	Event ID 4688: A new process has been created.

Rule body

title: Exploiting CVE-2019-1388
id: 02e0b2ea-a597-428e-b04a-af6a1a403e5c
status: stable
description: Detects an exploitation attempt in which the UAC consent dialogue is used to invoke an Internet Explorer process running as LOCAL_SYSTEM
references:
    - https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1388
    - https://www.zerodayinitiative.com/blog/2019/11/19/thanksgiving-treat-easy-as-pie-windows-7-secure-desktop-escalation-of-privilege
author: Florian Roth (Nextron Systems)
date: 2019-11-20
modified: 2024-12-01
tags:
    - attack.privilege-escalation
    - attack.t1068
    - cve.2019-1388
    - detection.emerging-threats
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        ParentImage|endswith: '\consent.exe'
        Image|endswith: '\iexplore.exe'
        CommandLine|contains: ' http'
    selection_rights:
        - IntegrityLevel:
              - 'System'  # for Sysmon users
              - 'S-1-16-16384' # System
        - User|contains: # covers many language settings
              - 'AUTHORI'
              - 'AUTORI'
    condition: all of selection_*
falsepositives:
    - Unknown
level: critical

Stages and Predicates

Stage 0: `condition`

all of selection_*

Stage 1: `selection_img`

selection_img:
    ParentImage|endswith: '\consent.exe'
    Image|endswith: '\iexplore.exe'
    CommandLine|contains: ' http'

Stage 2: `selection_rights`

selection_rights:
    - IntegrityLevel:
          - 'System'
          - 'S-1-16-16384'
    - User|contains:
          - 'AUTHORI'
          - 'AUTORI'

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`CommandLine`	match	`http` corpus 3 (sigma 2, chronicle 1)	`field:"CommandLine" kind:match value:" http"`
`Image`	ends_with	`\iexplore.exe` corpus 4 (sigma 4)	`field:"Image" kind:ends_with value:"\iexplore.exe"`
`IntegrityLevel`	eq	`S-1-16-16384` corpus 30 (sigma 22, splunk 4, elastic 3, kusto 1) `System` corpus 30 (sigma 22, splunk 4, elastic 3, kusto 1)	`field:"IntegrityLevel" kind:eq`
`ParentImage`	ends_with	`\consent.exe` corpus 2 (sigma 2)	`field:"ParentImage" kind:ends_with value:"\consent.exe"`
`User`	match	`AUTHORI` corpus 14 (sigma 14) `AUTORI` corpus 14 (sigma 14)	`field:"user" kind:match`

Exploiting CVE-2019-1388

MITRE ATT&CK coverage

Telemetry coverage

Rule body

Stages and Predicates

Stage 0: condition

Stage 1: selection_img

Stage 2: selection_rights

Indicators

Stage 0: `condition`

Stage 1: `selection_img`

Stage 2: `selection_rights`