Potential RDP Tunneling Via Plink

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

Execution of plink to perform data exfiltration and tunneling

MITRE ATT&CK coverage

Tactic	Techniques
Command & Control	`T1572` Protocol Tunneling

Event coverage

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

Stages and Predicates

Stage 1: `selection_a`

CommandLine|contains: ':127.0.0.1:3389'
Image|endswith: '\plink.exe'

Stage 2: `all of selection_b1`

CommandLine|contains: ':3389'
Image|endswith: '\plink.exe'

Stage 3: `all of selection_b2`

or:
CommandLine|contains: ' -P 22'
CommandLine|contains: ' -P 443'

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	`-P 22` `-P 443` `:127.0.0.1:3389` `:3389` corpus 3 (sigma 3)
`Image`	ends_with	`\plink.exe` corpus 2 (sigma 2)