Google is reiterating its stand against “unnatural” links. Webmasters need to be careful about unnatural links if they don’t want to be penalized by Google. The warning was issued on the Google Webmaster Blog.
Google’s stand against unnatural/low-quality/keyword-rich widget links is not new. And although widgets help improve user web site experience, sometimes the widgets can feature links which contain keyword rich anchor text. These unnatural links violate Google Webmaster Guidelines.
In a lot of instances site owners are completely unaware that unnatural links built into a widget are automatically getting placed on their site. Even if this is the case, Google will penalize the site with the site owner receiving a notification via their Search Console.
Google might also issue warnings if it finds links to a site are automatically included in widgets which are placed on different sites. When this happens site owners need to address the issue quickly by removing the links or by adding “nofollow” attributes to them while also sending a reconsideration request.
Taking it one step further, Google says that site owners should check for unnatural links in all widgets and take necessary action of either removing the links completely from the widget or including a nofollow attribute.