Surfers following up supposed online excerpts from the eagerly-awaited mid-season finale of Doctor Who will only find themselves stuck in the middle of survey scams, security researchers warn.

Searching from the upcoming episode A good man goes to war on YouTube leads to numerous results but all lead to third party websites, under the pretext that the clip is too long to be loaded onto YouTube.

Surfers going to these sites are told they need to complete a survey in order to unlock the supposed (non-existent) content. At best it's a waste of time; at worst the surveys might trick marks into handing over personal information or signing up for expensive subscription-based mobile services of dubious utility, such as daily horoscopes and the like.

Altogether it's best to wait for the real episode, due to air on the BBC on Saturday.

Chris Boyd, a security researcher at GFI Software, notes that the latest ruse is far from the first time scammers have targeted Who fans.

"The same thing happened when the last series finale was due to air," Boyd writes. "There was also a bit of an issue with various Doctor Who games doing the rounds, too. As always: avoid."

Although links to malware-tainted sites are yet to appear in the latest batch of scams, this remains a possibility.

"Everything we've seen so far is the usual fake video / survey nonsense, but there could well be malware in the offing between now and Saturday," said Boyd. ®