“Former Firefox developer Robert O’Callahan, now a free agent and safe from the PR tentacles of his corporate overlord, says that antivirus software is terrible, AV vendors are terrible, and that you should uninstall your antivirus software immediately—unless you use Microsoft’s Windows Defender, which is apparently okay.
A couple of months back, Justin Schuh, Google Chrome’s security chief, and indeed one of the world’s top infosec bods, said that antivirus software is ‘my single biggest impediment to shipping a secure browser.’ Further down the thread he explains that meddling AV software delayed Win32 Flash sandboxing ‘for over a year’ and that further sandboxing efforts are still on hold due to AV. The man-in-the-middle nature of antivirus also causes a stream of TLS (transport layer security) errors, says Schuh, which in turn breaks some elements of HTTPS/HSTS.”
Source: It might be time to stop using antivirus | Ars Technica