UAC Bypass Using Iscsicpl - ImageLoad

Status: test
Severity: high
Log source: category image_load, product windows
Author: Nasreddine Bencherchali (Nextron Systems)
Source: github.com/SigmaHQ/sigma

Detects the "iscsicpl.exe" UAC bypass technique that leverages a DLL Search Order hijacking technique to load a custom DLL's from temp or a any user controlled location in the users %PATH%

MITRE ATT&CK coverage

Tactic	Techniques
Privilege Escalation	`T1548.002` Abuse Elevation Control Mechanism: Bypass User Account Control

Telemetry coverage

Provider	Record / event type
Sysmon	Event ID 7: Image loaded

Rule body

title: UAC Bypass Using Iscsicpl - ImageLoad
id: 9ed5959a-c43c-4c59-84e3-d28628429456
status: test
description: Detects the "iscsicpl.exe" UAC bypass technique that leverages a DLL Search Order hijacking technique to load a custom DLL's from temp or a any user controlled location in the users %PATH%
references:
    - https://github.com/hackerhouse-opensource/iscsicpl_bypassUAC
    - https://twitter.com/wdormann/status/1547583317410607110
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-07-17
modified: 2022-07-25
tags:
    - attack.privilege-escalation
    - attack.t1548.002
logsource:
    product: windows
    category: image_load
detection:
    selection:
        Image: C:\Windows\SysWOW64\iscsicpl.exe
        ImageLoaded|endswith: '\iscsiexe.dll'
    filter:
        ImageLoaded|contains|all:
            - 'C:\Windows\'
            - 'iscsiexe.dll'
    condition: selection and not filter
falsepositives:
    - Unknown
level: high

Stages and Predicates

Stage 0: `condition`

selection and not filter

Stage 1: `selection`

selection:
    Image: C:\Windows\SysWOW64\iscsicpl.exe
    ImageLoaded|endswith: '\iscsiexe.dll'

Stage 2: `not filter`

filter:
    ImageLoaded|contains|all:
        - 'C:\Windows\'
        - 'iscsiexe.dll'

Exclusions

The rule actively suppresses these predicates.

Field	Kind	Excluded values	Search
`ImageLoaded`	match	`C:\Windows\`	`excludes:ImageLoaded` `field:"ImageLoaded" value:"C:\Windows\"`
`ImageLoaded`	match	`iscsiexe.dll`	`excludes:ImageLoaded` `field:"ImageLoaded" value:"iscsiexe.dll"`

Indicators

These rows show field, operator, and value matches.

Field	Kind	Values	Search
`Image`	eq	`C:\Windows\SysWOW64\iscsicpl.exe`	`field:"Image" kind:eq value:"C:\Windows\SysWOW64\iscsicpl.exe"`
`ImageLoaded`	ends_with	`\iscsiexe.dll`	`field:"ImageLoaded" kind:ends_with value:"\iscsiexe.dll"`