An expert has claimed that search engine optimization technique such as backlinking can go wrong if the site containing the hyperlinks is hosting malware.
Editor of Search Engine Journal Loren Baker said that a website's Google ranking may suffer if it links to or has links from malware-infested sites.
He recommended that webmasters use the Safe Browsing Diagnostic Checker from Google to find out whether websites have ever been investigated by the search giant for hosting malware.
'I highly suggest checking out the malware distribution history of a site, especially in the eyes of Google; if Google feels that the site is malicious, chances are linking to these bad sites, or building links from them, can hurt your rankings,' he said.
Google announced this month that it was changing the algorithm which worked out the 'quality score' of adverts on the site.
Specifically, the clickthrough rate (CTR) section of the code was being adjusted, to make it take into account the position of the advert in search results.