Multi-Stage Malware Attack Uses .JSE and PowerShell to Deploy Agent Tesla and XLoader
Apr 18, 2025
Malware / Email Security
A new multi-stage attack has been observed delivering malware families like Agent Tesla variants, Remcos RAT, and XLoader. "Attackers increasingly rely on such complex delivery mechanisms to evade detection, bypass traditional sandboxes, and ensure successful payload delivery and execution," Palo Alto Networks Unit 42 researcher Saqib Khanzada said in a technical write-up of the campaign. The starting point of the attack is a deceptive email that poses as an order request to deliver a malicious 7-zip archive attachment, which contains a JavaScript encoded (.JSE) file. The phishing email, observed in December 2024, falsely claimed that a payment had been made and urged the recipient to review an attached order file. Launching the JavaScript payload triggers the infection sequence, with the file acting as a downloader for a PowerShell script from an external server. The script, in turn, houses a Base64-encoded payload that's subsequently deciphered, written to the Wi...