Mstsc.EXE Execution With Local RDP File

Severity: low
Author: Nasreddine Bencherchali (Nextron Systems), Christopher Peacock @securepeacock
Source: upstream

Detects potential RDP connection via Mstsc using a local ".rdp" file

MITRE ATT&CK coverage

Tactic	Techniques
Command & Control	`T1219.002` Remote Access Tools: Remote Desktop Software

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `all of selection_img`

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

Stage 2: `all of selection_cli`

or:
CommandLine|endswith: .rdp
CommandLine|endswith: '.rdp"'

Stage 3: `not 1 of filter_optional_wsl`

CommandLine|contains: 'C:\ProgramData\Microsoft\WSL\wslg.rdp'
ParentImage: 'C:\Windows\System32\lxss\wslhost.exe'

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`	ends_with	`.rdp` corpus 2 (sigma 2) `.rdp"` corpus 2 (sigma 2)
`CommandLine`	match	`C:\ProgramData\Microsoft\WSL\wslg.rdp` corpus 2 (sigma 2)
`Image`	ends_with	`\mstsc.exe` corpus 5 (sigma 5)
`OriginalFileName`	eq	`mstsc.exe` corpus 4 (sigma 4)
`ParentImage`	eq	`C:\Windows\System32\lxss\wslhost.exe` corpus 2 (sigma 2)