Online ads provider Adform was hacked on July 27, after it began serving malicious code. The breach is detailed in its annual report, which says it serves 1.5 billion ads daily. Security researcher Kevin Beaumont first revealed the incident, noting that the ad‑loading script was tampered with to trigger in a victim’s browser. The code repeatedly replaces a user’s clipboard entry with the attacker’s crypto wallet addresses every three seconds, ensuring that any accidental paste sends funds to the hacker instead of the intended destination.

Beaumont warned that any downstream website using Adform can compromise visitors’ devices with the same malware. While Adform has issued a statement and is still investigating whether attackers accessed browsing‑history data, it has not disclosed how many users were affected or how the breach began. An ad blocker—such as uBlock Origin or Filtr/Wipr—would have prevented the malicious script from loading, illustrating the practical benefit of blocking ads.

The incident underlines why ad blockers are not just about privacy but also about protecting users from malware that can hijack even their crypto transactions. It is a stark reminder that the ad ecosystem's vulnerabilities can turn everyday browsing into a vector for theft.