Phishing Campaign Uses UpCrypter in Fake Voicemail Emails to Deliver RAT Payloads

Cybersecurity researchers have flagged a new phishing campaign that's using fake voicemails and purchase orders to deliver a malware loader called UpCrypter .

The campaign leverages "carefully crafted emails to deliver malicious URLs linked to convincing phishing pages," Fortinet FortiGuard Labs researcher Cara Lin said . "These pages are designed to entice recipients into downloading JavaScript files that act as droppers for UpCrypter."

Attacks propagating the malware have been primarily targeting manufacturing, technology, healthcare, construction, and retail/hospitality sectors across the world since the start of August 2025. The vast majority of the infections have been observed in Austria, Belarus, Canada, Egypt, India, and Pakistan, among others.

UpCrypter functions as a condu