Blackhole is one of the most popular crimeware toolkits serving browser-based exploits from compromised or malicious websites. Their end goal is to deliver malware (ransomware, banking trojans etc) onto unsuspecting visitors.
Pinterest is a really cool service where you can literally spend hours finding the most amazing ideas in a friendlier and more visual way than any other search engine.
The ‘virtual pin-board’ social site, has gained a lot of momentum and become one of the highest referral traffic sites for retailers.
As such, it is not a big surprise that it is a popular choice for scammers and malware authors.
Dubious online pharmaceutical companies use and abuse Pinterest to promote their ‘products’: