Potential Arbitrary Command Execution Using Msdt.EXE

Severity: high
Author: Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detects processes leveraging the "ms-msdt" handler or the "msdt.exe" binary to execute arbitrary commands as seen in the follina (CVE-2022-30190) vulnerability

MITRE ATT&CK coverage

Tactic	Techniques
Defense Evasion	`T1202` Indirect Command Execution

Event coverage

Provider	Event ID	Title
Sysmon	1	Process creation

Stages and Predicates

Stage 1: `selection_img`

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

Stage 2: `selection_cmd_inline`

CommandLine|contains: 'IT_BrowseForFile='

Stage 3: `all of selection_cmd_answerfile_flag`

CommandLine|contains: ' PCWDiagnostic'

Stage 4: `all of selection_cmd_answerfile_param`

CommandLine|contains: ' -af '

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	`-af` corpus 2 (sigma 2) `PCWDiagnostic` `IT_BrowseForFile=`
`Image`	ends_with	`\msdt.exe` corpus 10 (sigma 10)
`OriginalFileName`	eq	`msdt.exe` corpus 6 (sigma 6)

Potential Arbitrary Command Execution Using Msdt.EXE

MITRE ATT&CK coverage

Event coverage

Stages and Predicates

Stage 1: selection_img

Stage 2: selection_cmd_inline

Stage 3: all of selection_cmd_answerfile_flag

Stage 4: all of selection_cmd_answerfile_param

Indicators

Stage 1: `selection_img`

Stage 2: `selection_cmd_inline`

Stage 3: `all of selection_cmd_answerfile_flag`

Stage 4: `all of selection_cmd_answerfile_param`