Suspicious PowerShell Invocations - Generic - PowerShell Module

Severity: high
Author: Florian Roth (Nextron Systems)
Source: upstream

Detects suspicious PowerShell invocation command parameters

MITRE ATT&CK coverage

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

Event coverage

Provider	Event ID	Title
PowerShell	4103	Payload Context: ContextInfo User Data: UserData.

Stages and Predicates

Stage 1: `all of selection_encoded`

or:
ContextInfo|contains: ' -EncodedCommand '
ContextInfo|contains: ' -ec '
ContextInfo|contains: ' -enc '

Stage 2: `all of selection_hidden`

or:
ContextInfo|contains: ' -w 1 '
ContextInfo|contains: ' -w hidden '
ContextInfo|contains: ' -window hidden '
ContextInfo|contains: ' -windowstyle hidden '

Stage 3: `all of selection_noninteractive`

or:
ContextInfo|contains: ' -noni '
ContextInfo|contains: ' -noninteractive '

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
`ContextInfo`	match	`-EncodedCommand` `-ec` `-enc` `-noni` `-noninteractive` `-w 1` `-w hidden` `-window hidden` `-windowstyle hidden`