Event Triggered Execution: Accessibility Features T1546.008

Tactics: Privilege Escalation, Persistence

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.

Events covered

9 catalog events are tagged with this technique by at least one rule.

Authoring guide

Patterns shared across the 22 rules above: which fields they filter on, what specific values they look for, and what they exclude. The catalog normalizes field names across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.

Fields filtered most (27 distinct)

The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.

FieldRulesHowSample values
CommandLine14contains 9, regex_match 3, match 2(?i)Debugger.+\x5c(cmd|pwsh|powershell)\.exe, displayswitch.exe, (?i)(sethc|utilman|osk|Magnify|Narrator|DisplaySwitch|atb..., magnify.exe, narrator.exe
EventID7eq 71, 4688, 13, 4103, 4657
Image6ends_with 5, contains 1\cmd.exe, \cscript.exe, \mshta.exe, \powershell.exe, \powershell_ise.exe
parent_process_name4ends_with 1, eq 1, is_null 1, regex_match 1(?i)winlogon\.exe, Utilman.exe, \winlogon.exe, winlogon.exe
OriginalFileName3eq 2, starts_with 1?, cmd.exe, secedit
ParentImage3ends_with 3\winlogon.exe
TargetObject3ends_with 2, match 1\software\microsoft\windows nt\currentversion\image file..., (?i)debugger, \software\microsoft\windows nt\currentversion\image file..., \software\microsoft\windows nt\currentversion\image file..., \software\microsoft\windows nt\currentversion\image file...
process_name3regex_match 2, ends_with 1(?i)(cmd|cscript|mshta|powershell|pwsh|regsvr32|rundll32|..., cmd.exe
EventType2eq 2AUDIT_FAILURE, CreateKey, SetValue
TargetFilename2contains 1, ends_with 1\\\\windows\\\\system32\\\\atbroker.exe, \\\\windows\\\\system32\\\\displayswitch.exe, \\\\windows\\\\system32\\\\magnify.exe, \seth2c.exe, \sethc.exe
Type2eq 2
signature_id2contains 21, 13, 4657, 4688
AccessReason1contains 1%4417: %%1805
Details1match 1(?i)(cmd|pwsh|powershell)\.exe
EfectiveCommand1regex_match 1regexEmpire

Top indicator values (121 distinct)

Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique. Click a value to expand the rules under this technique that use it.

FieldKindValueRules (here)Corpus reach
CommandLinecontains
sethc.exe
44
CommandLinecontains
displayswitch.exe
33
CommandLinecontains
magnify.exe
33
CommandLinecontains
narrator.exe
33
CommandLinecontains
osk.exe
33
CommandLinecontains
utilman.exe
33
CommandLinecontains
-encodedcommand
13
CommandLinecontains
/cfg
12
CommandLinecontains
/configure
12
CommandLinecontains
/db
12
CommandLinecontains
/export
12
CommandLinecontains
/y
1
CommandLinecontains
\cmd.exe
1
CommandLinecontains
\currentversion\image file execution options\
1
EventIDeq
1
3237
EventIDeq
4688
3313
Imageends_with
\cmd.exe
3130
Imageends_with
\powershell.exe
2182
Imageends_with
\pwsh.exe
2168
ParentImageends_with
\winlogon.exe
35
CommandLinematch
(?i)Debugger.+\x5c(cmd|pwsh|powershell)\.exe
22
CommandLineregex_match
(?i)(sethc|utilman|osk|Magnify|Narrator|DisplaySwitch|atbroker|HelpPane)\.exe
22
TargetObjectends_with
\software\microsoft\windows nt\currentversion\image file execution...
22
TargetObjectends_with
\software\microsoft\windows nt\currentversion\image file execution...
22
TargetObjectends_with
\software\microsoft\windows nt\currentversion\image file execution...
22
TargetObjectends_with
\software\microsoft\windows nt\currentversion\image file execution...
22
TargetObjectends_with
\software\microsoft\windows nt\currentversion\image file execution...
22
TargetObjectends_with
\software\microsoft\windows nt\currentversion\image file execution...
22
process_nameregex_match
(?i)(cmd|cscript|mshta|powershell|pwsh|regsvr32|rundll32|wscript|wt)\.exe
22
AccessReasoncontains
%4417: %%1805
1

Exclusions (23 distinct)

Field/operator/value combinations excluded by rules under this technique (top-level not() clauses), sorted by how many rules exclude each. These are the false-positive paths the community has learned to filter out. A new rule that ignores the high-count entries here will likely fire on the same noisy paths. Click a value to expand the rules under this technique that exclude it.

FieldKindValueRules excluding
EventDatacontains
gc_service.exe
1
EventDatacontains
gc_worker.exe
1
OriginalFileNamecontains
atbroker.exe
1
OriginalFileNamecontains
displayswitch.exe
1
OriginalFileNamecontains
magnify.exe
1
OriginalFileNamecontains
narrator.exe
1
OriginalFileNamecontains
osk.exe
1
OriginalFileNamecontains
screenmagnifier.exe
1
OriginalFileNamecontains
sethc.exe
1
OriginalFileNamecontains
sr.exe
1
OriginalFileNamecontains
utilman.exe
1
OriginalFileNamecontains
utilman2.exe
1
OriginalFileNamein
atbroker.exe
1
OriginalFileNamein
displayswitch.exe
1
OriginalFileNamein
magnify.exe
1

Rules under this technique

Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.

Platform (all)
Domain (all)

Sigma 13 rules

Elastic 1 rule

Splunk 6 rules

Kusto 2 rules