Known false positives
- Actions of a legitimate telnet client
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Execution | |
| Privilege Escalation | |
| Stealth |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 7: Image loaded |
Rule body
title: UAC Bypass With Fake DLL
id: a5ea83a7-05a5-44c1-be2e-addccbbd8c03
status: test
description: Attempts to load dismcore.dll after dropping it
references:
- https://steemit.com/utopian-io/@ah101/uac-bypassing-utility
author: oscd.community, Dmitry Uchakin
date: 2020-10-06
modified: 2022-12-25
tags:
- attack.persistence
- attack.privilege-escalation
- attack.execution
- attack.stealth
- attack.t1548.002
- attack.t1574.001
logsource:
category: image_load
product: windows
detection:
selection:
Image|endswith: '\dism.exe'
ImageLoaded|endswith: '\dismcore.dll'
filter:
ImageLoaded: 'C:\Windows\System32\Dism\dismcore.dll'
condition: selection and not filter
falsepositives:
- Actions of a legitimate telnet client
level: high
Stages and Predicates
Stage 0: condition
selection and not filterStage 1: selection
selection:
Image|endswith: '\dism.exe'
ImageLoaded|endswith: '\dismcore.dll'
Stage 2: not filter
filter:
ImageLoaded: 'C:\Windows\System32\Dism\dismcore.dll'
Exclusions
The rule actively suppresses these predicates.
| Field | Kind | Excluded values | Search |
|---|---|---|---|
ImageLoaded | eq | C:\Windows\System32\Dism\dismcore.dll | excludes:ImageLoaded field:"ImageLoaded" value:"C:\Windows\System32\Dism\dismcore.dll" |
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
Image | ends_with |
| field:"Image" kind:ends_with value:"\dism.exe" |
ImageLoaded | ends_with |
| field:"ImageLoaded" kind:ends_with value:"\dismcore.dll" |