RDP Connection Allowed Via Netsh.EXE

Severity: high
Author: Sander Wiebing
Source: upstream

Detects usage of the netsh command to open and allow connections to port 3389 (RDP). As seen used by Sarwent Malware

MITRE ATT&CK coverage

Tactic	Techniques
Defense Evasion	`T1562.004` Impair Defenses: Disable or Modify System Firewall

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`

or:
CommandLine|contains: allow
CommandLine|contains: portopening
CommandLine|contains: 3389
CommandLine|contains: 'add '
CommandLine|contains: 'firewall '
CommandLine|contains: 'tcp '

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	`3389` `add` corpus 9 (sigma 9) `allow` `firewall` corpus 2 (sigma 2) `portopening` `tcp`
`Image`	ends_with	`\netsh.exe` corpus 16 (sigma 16)
`OriginalFileName`	eq	`netsh.exe` corpus 14 (sigma 14)