The 60-second viral shows two different male hands taking the drink, which is precariously balanced on the small of the woman's back, before another woman reaches up and grabs it.
Drinks giant Diageo has ordered YouTube to take down the clip, but it can still be easily found on the video sharing website.
The company issued a statement to Brand Republic which said: "Guinness is in no way associated with this video, and approached YouTube to have it removed. We are proud of our brands, and our commitment to responsible marketing, and this is not how we want our brand portrayed.
"We made this clear in a statement on the video's site as soon as it was drawn to our attention, the producer of the video also made it clear that the material was not associated with Guinness, and the original video has now been removed from YouTube."
However, YouTube members are encouraging others users to share the bogus ad in the knowledge that Diageo are demanding a clampdown on its distribution.
YouTube user Rupert Merdok posted the following comment alongside the video: "Diageo wants to distance from that great fake and instructed YouTube to remove it, but I think this video should live forever!!! Copy as many times as u can!!"
A YouTube member called Deschatz has taken responsibility for making the video, which he said was created "for fun". A recent post by Deschatz said: "Diageo PLC and YouTube have taken down the hoax ad I did for fun. So, folks, it's all over. No more good times for anyone."