Use NTFS Short Name in Command Line

Severity: medium
Author: frack113, Nasreddine Bencherchali (Nextron Systems)
Source: upstream

Detect use of the Windows 8.3 short name. Which could be used as a method to avoid command-line detection

MITRE ATT&CK coverage

Tactic	Techniques
Defense Evasion	`T1564.004` Hide Artifacts: NTFS File Attributes

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`

or:
CommandLine|contains: '~1.bat'
CommandLine|contains: '~1.dll'
CommandLine|contains: '~1.exe'
CommandLine|contains: '~1.hta'
CommandLine|contains: '~1.js'
CommandLine|contains: '~1.msi'
CommandLine|contains: '~1.ps1'
CommandLine|contains: '~1.vbe'
CommandLine|contains: '~1.vbs'
CommandLine|contains: '~2.bat'
CommandLine|contains: '~2.dll'
CommandLine|contains: '~2.exe'
CommandLine|contains: '~2.hta'
CommandLine|contains: '~2.js'
CommandLine|contains: '~2.msi'
CommandLine|contains: '~2.ps1'
CommandLine|contains: '~2.vbe'
CommandLine|contains: '~2.vbs'

Stage 2: `not filter`

or:
CommandLine|contains: 'C:\xampp\vcredist\VCREDI~1.EXE'
ParentImage|endswith: '\WebEx\WebexHost.exe'
ParentImage|endswith: '\thor\thor64.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`	match	`C:\xampp\vcredist\VCREDI~1.EXE` `~1.bat` `~1.dll` `~1.exe` `~1.hta` `~1.js` `~1.msi` `~1.ps1` `~1.vbe` `~1.vbs` `~2.bat` `~2.dll` `~2.exe` `~2.hta` `~2.js` `~2.msi` `~2.ps1` `~2.vbe` `~2.vbs`
`ParentImage`	ends_with	`\WebEx\WebexHost.exe` corpus 3 (sigma 3) `\thor\thor64.exe` corpus 3 (sigma 3)