Malvertising scams are likely to continue surging through the coming month. Malicious actors know that online retail spikes during the holiday season, so they increase their efforts to spread ad malware rather than good cheer. Retailers tend to prioritize customer experience over data security, so its important to understand how to avoid malvertising scams and prevent opportunistic threat actors from affecting your network. The Zirconium group created and operated 28 fake ad agencies to distribute malvertising campaigns and was responsible for 1 billion impressions.”]
Source: https://securityintelligence.com/tis-the-season-for-spreading-ad-malware/