Detection rules › Sigma

Exploiting CVE-2019-1388

Status
stable
Severity
critical
Log source
product windows, category process_creation
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

TacticTechniques
Privilege EscalationT1068 Exploitation for Privilege Escalation

Event coverage

Rule body yaml

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

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
CommandLinematch
  • http corpus 3 (sigma 2, chronicle 1)
Imageends_with
  • \iexplore.exe corpus 5 (sigma 5)
IntegrityLeveleq
  • S-1-16-16384 corpus 29 (sigma 22, splunk 4, elastic 3)
  • System corpus 29 (sigma 22, splunk 4, elastic 3)
ParentImageends_with
  • \consent.exe corpus 2 (sigma 2)
Usermatch
  • AUTHORI corpus 14 (sigma 14)
  • AUTORI corpus 14 (sigma 14)