A large spam campaign observed on Twitter directed users to malicious websites that exploited vulnerabilities in browser plug-ins to infect their computers with rogue antivirus programs. Researchers from antivirus firm Kaspersky Lab counted 4,148 tweets containing malicious links being sent from 540 compromised Twitter accounts. The high variation of links, messages and hijacked accounts used in this spam campaign could explain why Twitter’s automated spam filters weren’t successful at blocking it. Even though scareware is not as prevalent these days as it was a couple of years ago, sophisticated attack campaigns like this one still play an important role in cybercriminal ecosystem.”]