Vulnerability in McAfee Chrome Extension?

Found a rare bug coming from a user and we saw this...

https://forums.mcafee.com/t5/Cybercrime-Phishing/Critical-bug-on-WebAdvisor-chrome-extension/td-p/731011

Literally the extension for an antivirus was hacked?

Submission says:

Version 8.1.0.4679 has a bug in one of scripts: page_crypto_mining.js at line 23:525 (minified version). There is TypeError: 's.startsWith is not a function'. It breaks page scripts on different websites which use arraybuffer. I think this is critical bug.