PDFSider Windows malware deployed on Fortune 100 firm’s network

New PDFSider Windows malware deployed on Fortune 100 firm’s network www.bleepingcomputer.com/news/secu… Ransomware attackers targeting a Fortune 100 company in the financial sector used a new malware strain, dubbed PDFSider, to deliver malicious payloads on Windows systems. The attackers relied on social engineering to gain remote access, impersonating technical support personnel and attempting to trick employees into installing Microsoft’s Quick Assist tool. Researchers at cybersecurity firm Resecurity identified PDFSider during an incident response engagement and described it as a stealthy backdoor designed for long-term access, noting that it exhibits characteristics commonly associated with advanced persistent threat (APT) tradecraft.