The hypothesis is that the detected jQuery code may be part of a multi-stage attack leveraging legitimate JavaScript to execute arbitrary commands or exfiltrate data. A SOC team should proactively hunt for this behavior in Azure Sentinel to identify potential command and control activities or data exfiltration attempts hidden within seemingly benign script payloads.
rule jquery_code_su_multi {
strings: $ = "=oQKpkyJ8dCK0lGbwNnLn42bpRXYj9GbENDft12bkBjM8V2Ypx2c8Rnbl52bw12bDlkUVVGZvNWZkZ0M85WavpGfsJXd8R1UPB1NywXZtFmb0N3box"
condition: any of them
}
This YARA rule can be deployed in the following contexts:
Scenario: Legitimate jQuery code in a web application
Filter/Exclusion: file.name contains "jquery.min.js" or file.path contains "/web/assets/jquery/"
Scenario: Scheduled job using jQuery for automated report generation
Filter/Exclusion: process.name contains "scheduled_task.exe" or process.args contains "generate_report"
Scenario: System update or patching process includes jQuery as a dependency
Filter/Exclusion: process.name contains "msiexec.exe" or file.name contains "jquery-3.6.0.msi"
Scenario: Admin task involving jQuery for internal tool development
Filter/Exclusion: user.name contains "admin" and process.name contains "vscode.exe" or file.path contains "/dev/tools/"
Scenario: Legacy system maintenance using jQuery for UI components
Filter/Exclusion: file.name contains "legacy_ui.js" or process.args contains "maintain_legacy_system"