The Golden Globe-nominated "Sherlock" star will take the role of the fugitive boss, who is currently living under sanctuary at the Ecuador embassy in London as he fights moves to extradite him to the US and Sweden, reported Daily Express.
Cumberbatch, 36, could be joined onscreen by another TV favourite, Downton Abbey's Dan Stevens, who is "in negotiation" for a role as a computer hacker in the film.
The as-yet-untitled movie will be produced by Steven Spielberg's DreamWorks company.
It will focus on the activities of those working for the website, which sparked controversy by leaking hundreds of top secret and classified US military and State department documents since it was formed in 2006.