detection.wiki

Detection rules › Sigma

DCOM InternetExplorer.Application Iertutil DLL Hijack - Security

Status
test
Severity
high
Log source
product windows, service security
Author
Roberto Rodriguez @Cyb3rWard0g, Open Threat Research (OTR)
Source
github.com/SigmaHQ/sigma

Detects a threat actor creating a file named iertutil.dll in the C:\Program Files\Internet Explorer\ directory over the network for a DCOM InternetExplorer DLL Hijack scenario.

MITRE ATT&CK coverage

TacticTechniques
Lateral MovementT1021.002 Remote Services: SMB/Windows Admin Shares, T1021.003 Remote Services: Distributed Component Object Model

Event coverage

ProviderEventTitle
Security-AuditingEvent ID 5145A network share object was checked to see whether client can be granted desired access.

Rule body yaml

title: DCOM InternetExplorer.Application Iertutil DLL Hijack - Security
id: c39f0c81-7348-4965-ab27-2fde35a1b641
status: test
description: Detects a threat actor creating a file named `iertutil.dll` in the `C:\Program Files\Internet Explorer\` directory over the network for a DCOM InternetExplorer DLL Hijack scenario.
references:
    - https://threathunterplaybook.com/hunts/windows/201009-RemoteDCOMIErtUtilDLLHijack/notebook.html
author: Roberto Rodriguez @Cyb3rWard0g, Open Threat Research (OTR)
date: 2020-10-12
modified: 2022-11-26
tags:
    - attack.lateral-movement
    - attack.t1021.002
    - attack.t1021.003
logsource:
    product: windows
    service: security
detection:
    selection:
        EventID: 5145
        RelativeTargetName|endswith: '\Internet Explorer\iertutil.dll'
    filter:
        SubjectUserName|endswith: '$'
    condition: selection and not filter
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: condition

selection and not filter

Stage 1: selection

selection:
    EventID: 5145
    RelativeTargetName|endswith: '\Internet Explorer\iertutil.dll'

Stage 2: not filter

filter:
    SubjectUserName|endswith: '$'

Exclusions

Top-level NOT(...) conjuncts: predicates this rule actively suppresses.

FieldKindExcluded values
SubjectUserNameends_with$

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
RelativeTargetNameends_with
  • \Internet Explorer\iertutil.dll