ATT&CK coverage › Technique

System Script Proxy Execution T1216

Adversaries may use trusted scripts, often signed with certificates, to proxy the execution of malicious files. Several Microsoft signed scripts that have been downloaded from Microsoft or are default on Windows installations can be used to proxy execution of other files. This behavior may be abused by adversaries to execute malicious files that could bypass application control and signature validation on systems.

Events covered

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

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon11FileCreate
Security-Auditing4688A new process has been created.

Authoring guide

Patterns shared across the 13 rules above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized 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 (6 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
CommandLine9match 9winrm, LoadAssemblyFromPath , LoadAssemblyFromNS , format:pretty, format:text
Image7ends_with 4, eq 2, starts_with 1\powershell.exe, \cmd.exe, C:\Windows\System32\, C:\Windows\SysWOW64\, \pwsh.exe
ParentImage5ends_with 5\powershell.exe, \pwsh.exe, \cscript.exe, \wscript.exe, \CustomShellHost.exe
ParentCommandLine2match 2{ Invoke-Pester -EnableExit ;, \WindowsPowerShell\Modules\Pester\, { Get-Help ", manage-bde.wsf
OriginalFileName2eq 2wscript.exe, cscript.exe
TargetFilename1ends_with 1, starts_with 1C:\Windows\System32\, C:\Windows\SysWOW64\, WsmTxt.xsl

Top indicator values (49 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.

FieldKindValueRules (here)Corpus reach
CommandLinematchwinrm22
Imageends_with\powershell.exe2143
CommandLinematch;22
Imageends_with\cmd.exe292
ParentImageends_with\powershell.exe216
ParentImageends_with\pwsh.exe216
CommandLinematchLoadAssemblyFromPath 1
CommandLinematchLoadAssemblyFromNS 1
Imagestarts_withC:\Windows\SysWOW64\116
CommandLinematchformat:"pretty"1
CommandLinematchformat:"text"1
CommandLinematchformat:text1
Imagestarts_withC:\Windows\System32\116
CommandLinematchformat:pretty1
TargetFilenamestarts_withC:\Windows\SysWOW64\12
TargetFilenameends_withWsmTxt.xsl1
TargetFilenamestarts_withC:\Windows\System32\13
TargetFilenameends_withWsmPty.xsl1
CommandLinematchPester1
CommandLinematch\?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.

Sigma 13 rules