CAPTCHA smuggling
Manuel Egele, Leyla Bilge, Engin Kirda, Christopher Kruegel · 2010
CAPTCHAs protect online resources and services from automated access. From an attacker's point of view, they are typically perceived as an annoyance that prevents the mass creation of accounts or the automated posting of messages. Hence, miscreants strive to effectively bypass these protection mechanisms, using techniques such as optical character recognition or machine learning. However, as CAPTCHA systems evolve, they become more resilient against automated analysis approaches.