Despite its technical strengths, CIS 2025 has faced criticism in several areas:

The sandbox technology is Comodo’s crown jewel. In the 2025 update, the sandbox engine has been optimized for performance. When you download a file from the internet, Comodo runs it in an isolated virtual container. If the file turns out to be malicious, it cannot access your real hard drive, registry, or personal data. It simply deletes the infection upon restart. The 2025 version boasts faster resource allocation, meaning users experience less lag when running sandboxed applications.

Comodo has optimized its footprint. While sandboxing can be memory-intensive, the 2025 version utilizes modern multi-core processors efficiently, ensuring that gaming and video streaming remain smooth even while a background scan is active.

Historically, Comodo was criticized for having a steep learning curve and being "noisy" (too many pop-up alerts asking for permission).