Command Line Execution with Suspicious URL and AppData Strings

Severity: medium
Author: Florian Roth (Nextron Systems), Jonhnathan Ribeiro, oscd.community
Source: upstream

Detects a suspicious command line execution that includes an URL and AppData string in the command line parameters as used by several droppers (js/vbs > powershell)

MITRE ATT&CK coverage

Tactic	Techniques
Execution	`T1059.001` Command and Scripting Interpreter: PowerShell, `T1059.003` Command and Scripting Interpreter: Windows Command Shell
Command & Control	`T1105` Ingress Tool Transfer

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`

CommandLine|contains: '%AppData%'
CommandLine|contains: '://'
CommandLine|contains: http
Image|endswith: '\cmd.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.