Today's earlier rumor about a viral outbreak in Grand Theft Auto IV has borne fruit – icky, decaying, zombie fruit. It turns out that the zombie apocalypse has come to Liberty City, but not in the form of DLC. It's a tweak that's been made to the game's multiplayer modes just in time for Halloween.

According to a news update on the Rockstar Social Club site, a virus introduced into the game world turns players into zombies (or at least bestows them with the zombie skin) and "can be contracted in any and all multiplayer modes and is spread when an unsuspecting player kills someone who has the infection." The post also mentions that signs of infection include gaining access to the zombie skin in multiplayer or earning the "Let Sleeping Rockstars Lie" Achievement (on 360).

The Social Club site has been updated with a new community feature that lets registered users check to see if they've been "infected," as well as access US and world maps displaying the spread of the "disease." We've contacted Rockstar on the off chance they're willing to spill some details on how long we'll be riding out this outbreak.