Comodo Internet Security (CIS) is developed and distributed by Comodo Group, a freemium Internet security suite that includes an antivirus program, personal firewall, sandbox, host-based intrusion prevention system (HIPS) and website filtering.

Defense+ by default refuses any unknown program to install or execute except when specifically allowed by the user or when the file appears on Comodo's whitelist.

[5] CIS v6, released February 2013, provided a major revision of the user interface and significant new features such as a fully sandboxed desktop environment.

It includes extra functionality in creating rules and full support for Windows 10 October 2018 update.

[20][21] On 28 May 2009, Roboert Vamosi of PC World reviewed Comodo Internet Security 3.8 and gave it a score of 1 out of 5, criticizing it for its "disappointing malware detection" based on AV-TEST result and "limited feature set".

"[24] Also on the same date, Mike Williams of BetaNews.com reviewed Comodo Internet Security Pro 2013 and concluded "The program remains too complex for total PC beginners, we suspect.

The average user will appreciate its largely automatic operation, though, while experts enjoy the powerful tools and extreme configurability.

"[25] On 7 February 2013, Comodo Internet Security Complete v6 earned the PC Magazine Editor's Choice award.

Reubenking concluded "The biggest win for Comodo Internet Security Complete 2013 isn't in features, but in support.