Firewall Rule Update Via Netsh.EXE

Severity: medium
Author: X__Junior (Nextron Systems)
Source: upstream

Detects execution of netsh with the "advfirewall" and the "set" option in order to set new values for properties of a existing rule

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `all of selection_img`

or:
Image|endswith: '\netsh.exe'
OriginalFileName: netsh.exe

Stage 2: `all of selection_cli`

CommandLine|contains: ' firewall '
CommandLine|contains: ' set '

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	`firewall` corpus 2 (sigma 2) `set` corpus 4 (sigma 4)
`Image`	ends_with	`\netsh.exe` corpus 16 (sigma 16)
`OriginalFileName`	eq	`netsh.exe` corpus 14 (sigma 14)