Windows users

Cybersecurity experts have reported a significant increase in phishing emails targeting Microsoft Windows devices, linked to UpCrypter, a loader that installs remote access tools (RATs) for long-term access to compromised systems. These phishing emails often appear as missed voicemails or purchase orders, leading victims to counterfeit websites that prompt them to download a ZIP file containing a JavaScript dropper. This script executes PowerShell commands to connect to attacker-controlled servers, initiating further malware deployment. UpCrypter scans the system for security monitoring and can reboot to disrupt investigations if detected. If not, it downloads additional payloads, including PureHVNC for remote desktop access, DCRat for spying and data theft, and Babylon RAT for complete control over infected devices. Attackers use techniques like steganography, string obfuscation, and in-memory execution to evade detection. This phishing campaign, active since early August 2025, has affected various sectors, including manufacturing, technology, healthcare, construction, and retail/hospitality, with significant activity reported in countries like Austria, Belarus, Canada, Egypt, India, and Pakistan. Detections of this malware have doubled in two weeks, indicating a rapid escalation of the operation. Organizations are urged to implement robust email filtering and train employees to recognize these threats.