According to McAfee, Superman was the 'Most Toxic Superhero' with 16.5 per cent chances of landing on a website that has been tested positive for online threats.
For example, fans searching for "Superman and free torrent download", "Superman and watch", "Superman and free app" etc are at risk of running into online threats designed to steal personal information, it said.
Clicking on these "risky sites" and downloading files like pictures and videos exposes surfers or consumers to the risk of downloading viruses and malware, it added.
Following in the list were Thor (16.35 per cent chances) and Wonderwoman and Aquaman (15.7 per cent chances each).
Others in the list included Wolverine, Spiderman, Batman, Black Widow, Captain America, Green Lantern and Ghost Rider.
"With excitement building for the upcoming Batman vs Superman: Dawn of Justice film, it is no surprise that these superheroes top the list," McAfee said in a statement.
Last year, Aquaman had topped the list with 18.6 per cent chances of landing on a website that has been tested positive for online threats.
On steps to protect users from online threats, McAfee said if a search turns up a link to free content or too-good- to-be-true offers, they should be wary.
"Users should beware of content that prompts them to download anything before providing them with content. Free downloads are significantly the highest virus-prone search terms," it said.
It added that anyone searching for videos or files to download should be careful as not to unleash malware on their computer.
McAfee is a wholly-owned subsidiary of world's largest computer chip maker Intel Corporation.