We have written about the threat actor eGobbler extensively on our blog over the last year as they’ve continued to emerge as a prolific source of malvertising. It’s not uncommon for their campaigns to compromise up to hundreds of millions of programmatic ad impressions in a matter of hours and the impact from their ongoing activity is felt across the United States and Europe.

Over the past 6 months, the threat group has leveraged obscure browser bugs in order to engineer bypasses for built-in browser mitigations against pop-ups and forced redirections.

This blog post will provide overviews and proof of concepts for both browser exploits. The first exploit that we reported on April 11, 2019 impacts Chrome versions prior to 75 on iOS. The second, which we reported on Aug. 7 was fixed in iOS 13 / Safari 13.0.1 on Sept. 19, impacts WebKit based browsers.