Read Contents From Stdin Via Cmd.EXE

Severity: medium
Author: frack113, Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detect the use of "<" to read and potentially execute a file via cmd.exe

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059.003` Command and Scripting Interpreter: Windows Command Shell

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `all of selection_cmd`

or:
Image|endswith: '\cmd.exe'
OriginalFileName: Cmd.Exe

Stage 2: `all of selection_cli`

CommandLine|contains: '<'

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	`<`
`Image`	ends_with	`\cmd.exe` corpus 92 (sigma 92)
`OriginalFileName`	eq	`Cmd.Exe` corpus 32 (sigma 30, splunk 2)