PDFSIDER Malware Actively Exploited to Evade Antivirus and EDR Defenses

**Executive Summary:** PDFSIDER is a sophisticated backdoor delivered via spear-phishing ZIPs that side-loads a malicious cryptbase.dll alongside a signed PDF24 executable to bypass EDR; it runs mainly in memory, implements AES-256-GCM AEAD for encrypted C2 over DNS (port 53), and contains sandbox/VM detection and other evasion techniques, with provided IOCs for detection and response.