Sticky Key Like Backdoor Execution

Severity: critical
Author: Florian Roth (Nextron Systems), @twjackomo, Jonhnathan Ribeiro, oscd.community
Source: upstream

Detects the usage and installation of a backdoor that uses an option to register a malicious debugger for built-in tools that are accessible in the login screen

MITRE ATT&CK coverage

Tactic	Techniques
Persistence	`T1546.008` Event Triggered Execution: Accessibility Features
Privilege Escalation	`T1546.008` Event Triggered Execution: Accessibility Features

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation
Security-Auditing	4688	A new process has been created.

Stages and Predicates

Stage 1: `selection`

or:
CommandLine|contains: DisplaySwitch.exe
CommandLine|contains: Magnify.exe
CommandLine|contains: Narrator.exe
CommandLine|contains: osk.exe
CommandLine|contains: sethc.exe
CommandLine|contains: utilman.exe
or:
Image|endswith: '\cmd.exe'
Image|endswith: '\cscript.exe'
Image|endswith: '\mshta.exe'
Image|endswith: '\powershell.exe'
Image|endswith: '\pwsh.exe'
Image|endswith: '\regsvr32.exe'
Image|endswith: '\rundll32.exe'
Image|endswith: '\wscript.exe'
Image|endswith: '\wt.exe'
ParentImage|endswith: '\winlogon.exe'

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.