Neutralizing Malicious Email Attachments: How Attackers Evade Sandboxes

The Evolution Beyond Macro-Enabled Word Docs

With Microsoft disabling VBA macros by default in Office files downloaded from the web, adversaries shifted to ISO containers, password-protected ZIP/7z archives, SVG vector files, and LNK shortcut files.

Sandbox Evasion Techniques

Malware authors incorporate deliberate execution delays (sleeping for 10 minutes to exceed sandbox inspection timeouts) and check for mouse movement or virtualization artifacts before executing malicious payloads.

Gateway Policy Lockdown

Implement tenant-wide transport rules to outright block high-risk file types (.iso, .vhd, .exe, .scr, .bat, .hta) and configure automated decryption inspection for password-protected archives where passwords are included in the email body.