Oolite Bulletins

Human solvers
CAPTCHA is vulnerable to a relay attack that uses humans to solve the puzzles. One approach involves relaying the puzzles to a group of human operators who can solve CAPTCHAs. In this scheme, a computer fills out a form and when it reaches a CAPTCHA, it gives the CAPTCHA to the human operator to solve.

Spammers pay about $0.80 to $1.20 for each 1,000 solved CAPTCHAs to companies employing human solvers in Bangladesh, China, India, and many other developing nations.[19] Other sources cite a price tag of as low as $0.50 for each 1,000 solved.[20]

Another approach involves copying the CAPTCHA images and using them as CAPTCHAs for a high-traffic site owned by the attacker. With enough traffic, the attacker can get a solution to the CAPTCHA puzzle in time to relay it back to the target site.[21] In October 2007, a piece of malware appeared in the wild which enticed users to solve CAPTCHAs in order to see progressively further into a series of striptease images.[22][23] A more recent view is that this is unlikely to work due to unavailability of high-traffic sites and competition by similar sites.[24]

These methods have been used by spammers to set up thousands of accounts on free email services such as Gmail and Yahoo!.[25] Since Gmail and Yahoo! are unlikely to be blacklisted by anti-spam systems, spam sent through these compromised accounts is less likely to be blocked.

Ahruman wrote:

Evaluation time. Thoughts?