Tumblr is dealing with an aggressive phishing campaign. Only recently launched, it aims to steal log-in credentials and employs many of the well-known social engineering tactics that scammers use on social media sites such as Facebook and Twitter.According to GFI Labs researchers Christopher Boyd and Jovi Umawing, the campaign began in mid June on the microblogging site, which claims to see 400 million page views a day. The campaign first began with an IQ test that was making the rounds, prompting users to test their IQ against other members.[See also:Social media risks: The basics]"Not long after this, the additional domains started to appear and then the full scale phish invasion took things up a level, with compromised accounts serving up a mixture of Tumblr hosted text and login credential submission forms served up by free webhosting accounts," researchers noted in a blog post. "While many of the compromised Tumblr accounts wanted you to login on the same page, many more besides were redirecting end-users to the tumblrlogin(dot)com website."The ruse now making the rounds now uses another tried-and-true social engineering tactic and promises users a glimpse of pornographic content once they "revalidate" their credentials by entering them into a fake log in page. The researchers said several domains are involved in the scam, including tumblriq(dot)com, tumblrlogin(dot)com and tumblrsecurity(dot)com."The problem has become so pervasive that regular Tumblr users are setting up dedicated anti phishing sites to advise users of the problem. One of these sites actually pointed us in the direction of one of the dropzones used for the stolen logins, and the problem does indeed seem to be out of control at this point."GFI Labs researchers say the data they saw contained 8,200 lines of text stretched across 304 pages of Microsoft Word."Even accounting for the inevitable duplicates and fake data that's still quite the goldmine of pilfered login credentials," they note."What does somebody want with that many Tumblr logins? We can only guess. The stolen accounts could be used as some form of advert affiliate money making scam, or maybe we could see lots of pages with survey popups pasted over them. There is the very real possibility that the Tumblr accounts are simply a way to test if those users are logging into other services with the same credentials - at that point, everything from email accounts to internet banking sites could be fair game."Boyd and Umawing, in their post, advise Tumblr users to get educated about phishing scams \u2014 fast. Because, much like Facebook and Twitter struggle at times with security, Tumblr will likely also be subjected to another attack in the future.