Powershell Inline Execution From A File

Severity: medium
Author: frack113
Source: upstream

Detects inline execution of PowerShell code from a file

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059.001` Command and Scripting Interpreter: PowerShell

Event coverage

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

Stages and Predicates

Stage 1: `all of selection_exec`

or:
CommandLine|contains: 'Invoke-Command '
CommandLine|contains: 'Invoke-Expression '
CommandLine|contains: 'icm '
CommandLine|contains: 'iex '

Stage 2: `all of selection_read`

or:
CommandLine|contains: 'cat '
CommandLine|contains: 'get-content '
CommandLine|contains: 'type '

Stage 3: `all of selection_raw`

CommandLine|contains: ' -raw'

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.

Field	Kind	Values
`CommandLine`	match	`-raw` `Invoke-Command` `Invoke-Expression` `cat` corpus 2 (sigma 2) `get-content` `icm` `iex` corpus 3 (sigma 3) `type` corpus 6 (sigma 6)