Chrome and Internet Explorer are the biggest sources of fraudulent ad traffic, according to research from FraudLogix.

Based on a study of 135m ad impressions in July, the report showed that non-human traffic accounted for 20.5 per cent of ad impressions served on Chrome, and a startling 50 per cent on Internet Explorer.

By comparison, other browsers analysed in the study – including Firefox, Safari and IE successor Microsoft Edge – all showed less than five per cent fraudulent impressions.

According to The Wall Street Journal, both Google and Microsoft questioned the methodology behind the study, claiming that it isn’t possible to accurately measure fraud at browser level – or at least, according to a Google statement, that its not “a helpful way of understanding this issue”.

However, FraudLogix believes that the higher proportion of fraud for these browser simply reflects their widespread adoption – Chrome accounted for 61 per cent of the traffic analysed, and Internet Explorer 16 per cent – which makes them a more attractive target.