Technique

Malvertising

Also known as: Malicious Advertising, Malicious Online Ads, Drive-by Download Advertising, Ad-based Malware Distribution

DELIVERY

Malvertising (malicious advertising) injects malware through legitimate ad networks, delivering payloads via infected display ads, pop-ups, or sponsored search results—often without requiring user clicks through drive-by downloads.

Common attack flows

How it fits in a scam

This technique shows up duringDELIVERY

Before

This is often where the scam begins.

After

Defense

How to defend against this

How to spot it

  • Ads with spelling errors or grammatical mistakes or low-quality graphics
  • Unrealistic offers like free prizes or urgent security warnings or too-good-to-be-true deals
  • Sponsored search result URLs that don't match advertised brand with subtle typos
  • Unexpected browser redirects to unfamiliar websites
  • Pop-ups appearing from unexpected sources on legitimate sites
  • Browser suddenly slowing or behaving erratically after viewing ads

Tools you can use

Seen in the wild

Where we’ve seen it

Commonly targets

Further reading