
While Valve reportedly banned him before (after doxxing other members of the community), Chaos has continued supporting his mods through links to outside downloads from Steam discussions. The NME report notes Chaos’ malicious code targets specific individuals hampering a machine’s performance if Steam IDs matched certain Cities: Skylines developers, modders, or other community members.Īt the time of publishing this article, it does appear that some mods listed under Chaos’ handle are still available. Suddenly you have tens of thousands of users who have effectively installed a trojan on their computer.”
Users install Harmony (redesigned) with the bundled with it. Those versions gain traction and users, and people come across them instead of the originals… and see Harmony (redesigned) marked as a dependency. The solution provided is to use his versions. “Users install Harmony (redesigned) for a particular reason, suddenly they get errors in popular mods.

Speaking to NME, a moderator for the Cities: Skylines subreddit explained Chaos, also known as Holy Water, may have distributed malware to as many as 35,000 players, and that he modifies well-known add-ons in order to quickly gain traction through “forking” those mods. To protect other players, the subreddit moderator links to multiple, legitimate sources for the additional tools, and a one-click unsubscribe for malicious versions - the thread is worth a quick pass if you’ve ever installed mods for the game. Mods like Harmony, Network Extensions, Traffic Manager: President Edition, and others have all been targeted by the malware reuploads. According to the post, Valve has removed several of these while others remain available. These mods aren’t the original sources of popular tools, but instead modified and reuploaded versions. The Reddit thread created by a sub moderator (via Eurogamer) documents malware found in Cities: Skylines add-ons and names ‘Chaos’ or ‘Holy Water’ as the creator of the malicious code. The creator of these mods was previously banned from Steam but returned under new usernames to upload their work.

Cities: Skylines players are being urged to check their mod subscriptions through Steam after reports that multiple popular add-ons may include malware.
