I frequently see strange hyperlinks in text on various webpages (including Avast!). If I hover over them, small adverts appear.
This will be followed by a new Chrome window opening with a link such as
http://www.gfdcv.com/sc?p=OTQ0MzY0NTAzMtHto01xOBa7bttbA3T8Q57sjeUaV3PMiFCgXEDFcBbwc%2FP9ZymccckXpc2iP3GIUZo6xj8iuA9UWRjinl%2BwON6n7jY4YRZ7hC3446rntLyUpVe5uqQJjRpENyvFZAGIiqFrclL0hb42XI0cJTLOxXFJYCqQ9Ceb83n0HkzFq6Yx0WdQeB%2F7%2FeQSlPUFyeqQGeqRcKS1EvajWfGygDJHGdst%2Fole7UlYtfvEC7K1wtrsfM6ZoOrlH6e0wpOK8TVRgdRR2V35bwIG8%2BGkw1VcrSluQmgBFHmmC6Jo%2FCiqZZehp4gzkzsD5cLlp5Y6aFwgzA%3D%3D&ia=0&t=1
Also, short video windows will open and play adverts for ski resorts and other such things.
I am working thru the instructions on the post “Logs to assist in cleaning malware”
Rob