Suspicious Encoded JScript Execution via WScript (via process_creation)

ATT&CK techniques

Execution

Recon
Resource Dev
Initial Access
Execution
- T1059.001PowerShell
- T1204.002Malicious File
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects Windows Script Host executing an encoded JScript file with the .jse extension, matching the Fenix botnet chain where a .url shortcut launches rfc.jse to stage a .NET loader. Encoded .jse files are rare in legitimate enterprise activity and are used here to hinder analysis before shellcode is injected into AuthHost.exe. This catches the early execution stage of the LATAM banking malware.

Reporting behind it

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Suspicious Encoded JScript Execution via WScript (via process_creation)

Pivot detection · T1059.001 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

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