Meme, which will initially work out of WCRS's offices from 6 May, will also seek business from non-WCRS clients. It is launching with briefs from The Number 118 118 and BMW's Mini brand.
Meme replaces WCRS's interactive division, eBrands, which was folded back into the agency two years ago.
Stephen Woodford, the chief executive of WCRS, said: "Meme gives more focus and entrepreneurial energy to our existing interactive offer, which we felt was strong enough to be established as a standalone agency."
The move is part of WCRS's strategy to create a number of satellite companies. These will include a PR and below-the-line shop that will operate independently of the creative agency and provide new revenue streams.
Anson Harris, who is the copywriter behind The Number's viral spoof of Honda's "cog" commercial, will be Meme's creative director, heading the agency alongside the commercial director, Faraaz Marghoob.
Marghoob, who previously worked at IBM Consulting, said: "Digital is a growth medium and we wanted to harness this. It's a sign of the times and where we see the market going. Tied to WCRS, we can build on its existing relationships while also picking up external business."
Meme will specialise in viral marketing, interactive television and online advertising and has already created a viral website for The Number, which is also scheduled to go live on 6 May.
The site will feature the duo from the 118 ads hosting their own TV show and appearing in a variety of amusing roles themed around their new guise as detectives.
The site will also put users in the director's chair, allowing them to create their own episodes of the show.