If you’re currently running third-party antivirus on your computer, remove it now. In case you’re considering buying one, don’t do it. Antivirus solutions are poison for the software ecosystem.

This is what Robert O'Callahan, a former Mozilla engineer, explains in a post on his blog, revealing how a security product can break down not necessarily Windows, but the other applications running on a computer.

“Antivirus software vendors are terrible; don't buy antivirus software, and uininstall it if you already have it (except, on Windows, for Microsoft's),” he says at the beginning of his post.

Specifically, O'Callahan points out that all antivirus solutions except for Microsoft’s actually do more harm on a system, as they create additional security flaws that can be exploited by attackers. He says Windows Defender is a “competent” piece of software, emphasizing that third-party security vendors do not follow their standard security practices and in the end expose users and their data.

“AV products poison the software ecosystem because their invasive and poorly-implemented code makes it difficult for browser vendors and other developers to improve their own security,” he continues.

The former Mozilla engineer then goes on to detail how some antivirus solutions blocked Firefox updates when the browser implemented ASLR in an attempt to actually offer users improved security. Users could no longer receive security updates for the browser, and Mozilla had no other option than working with antivirus developers on fixing these issues.

Users end up blaming software developers, not antivirus apps

So what’s the problem in working with antivirus vendors, you could ask? O'Callahan says that software developers spend too much time “dealing with AV-induced breakage,” and not on things that could actually improve user experience, only to find out that, in the end, antivirus companies can easily lead to users blaming their product.

“Users have been fooled into associating AV vendors with security and you don't want AV vendors bad-mouthing your product. AV software is broadly installed and when it breaks your product, you need the cooperation of AV vendors to fix it. (You can't tell users to turn off AV software because if anything bad were to happen that the AV software might have prevented, you'll catch the blame),” he continues.

“When your product crashes on startup due to AV interference, users blame your product, not AV. Worse still, if they make your product incredibly slow and bloated, users just think that's how your product is.”

Antivirus vendors are yet to provide a response to all these claims, but there’s no doubt that some of them will react with comments that will probably deny everything. And yet, the former Mozilla engineer brings forward some very interesting points, some of which users have been complaining about for a long time, including system slowdowns and blocked apps.