Detection rules › Kusto Query Language

Modification of Accessibility Features

Author
Vasileios Paschalidis
Source
upstream

'Adversaries may establish persistence and/or elevate privileges by executing malicious content triggered by accessibility features. Windows contains accessibility features that may be launched with a key combination before a user has logged in (ex: when the user is on the Windows logon screen). An adversary can modify the way these programs are launched to get a command prompt or backdoor without logging in to the system. Two common accessibility programs are C:\Windows\System32\sethc.exe, launched when the shift key is pressed five times and C:\Windows\System32\utilman.exe, launched when the Windows + U key combination is pressed. The sethc.exe program is often referred to as "sticky keys", and has been used by adversaries for unauthenticated access through a remote desktop login screen. [1] Ref: https://attack.mitre.org/techniques/T1546/008/'

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1546.008 Event Triggered Execution: Accessibility Features
Privilege EscalationT1546.008 Event Triggered Execution: Accessibility Features

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation

Stages and Predicates

Stage 1: source

Event

Stage 2: where

and
  EventID eq "1"
  EventLog eq "Microsoft-Windows-Sysmon/Operational"

Stage 3: parse

Stage 4: where

and
  not
    OriginalFileName match "OriginalFileNameList"
  Image match "ImagesList"

Stage 5: parse

Stage 6: summarize

Stage 7: extend

Stage 8: extend

Stage 9: extend

Stage 10: extend

Stage 11: extend

Stage 12: project-away

Exclusions

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

StageFieldKindExcluded values
1OriginalFileNamematchOriginalFileNameList

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
EventIDeq
  • 1 corpus 3 (splunk 3)
EventLogeq
  • Microsoft-Windows-Sysmon/Operational
Imagematch
  • ImagesList