This attack poses a minor threat. Corrective action may not be possible or is not required.
This signature detects suspicious activities associated with unwanted browser extension download and extension activity
Unwanted Browser Extension is a detection for browser hijackers which affect browsers like Internet Explorer, Microsoft Edge, Google Chrome, Mozilla Firefox etc. These extensions are usually installed by users themselves from web pages which promote specific tools for certain tasks, for example, file format converters. Users are usually redirected to such websites via malvertisement or through social engineering attack chains. On installation of such extensions, users might witness toolbars being added to browsers, browser start pages being changed, annoying browser pop ups etc.
No additional response is needed.
If you wish to access a website blocked by Intrusion Prevention, please go through the exclusion process listed at https://support.symantec.com/en_US/article.HOWTO80883.html to exclude the Intrusion Prevention detection blocking the given website.