what viral toolbar might that be ? any name ?
It was a search extender toolbar that was silently installed, when user browsed somewhere they shouldn't have by accident. Say you search on Amazon for a DVD, the user was then getting popups, from system tray, offering the same DVD at a cheaper price (completely uselessly in $ though) from web sites no one has ever heard of. Only present in the users account and did not need administrator privileges to install. Easily fixed by killing the user, so they won't do it again and shouting once again "in a corporate environment though shalt only use IE 11 where we manage it (and watch what you are doing well not actually but poops enough pants....)...".
We have seen similar under Chrome, where the authors of a legitimate toolbar (post code mapping toolbar) were mysteriously bought out and the tool bar was repurposed as an advert serving engine. Same updated toolbar didn't work in IE as MS didn't digitally sign it, so failed to update correctly. Thank goodness the group policy of enforcing signed code.
Also seen a re-complied Chrome installation .EXE files that were pre-infected, not just a Chrome installation wrapped in a virus, but actually built in. Also installable by a user without administrative privileges, so users get a "to see this kitten video, you must install Chrome, click here"....Bang user account gone... Also installed a proxy and remapped IE to it, so when user thought Chrome was misbehaving and went back to IE it did the same, except usually went wrong and page was incomplete and obviously wrong...
All were sorted user Sysinternals Autoruns, to see what was being loaded and where, deleting startup file and the remainder .EXE and .DLL got via standard virus checkers. Also Windows to Go booted on USB with virus checkers is handy...