'Cities: Skylines' Mods Banned From Steam Following Alleged Malware Discovery

KEY POINTS

A modder was banned after allegedly releasing mods with malicious code
Three mods related to the modder were taken down from Steam
The developers assured users that there was no malware in any of the existing workshop files

Three user-created mods from the Steam Workshop for the city-builder game “Cities: Skyline” were taken down and permanently banned following reports of malicious code that affected certain players.

Mod files uploaded by a user known as Chaos, later known as Holy Water, were removed from the Steam Workshop after players reported suspicious software behavior that began after certain mods were installed, according to a report from PC Gamer.

It turns out that Chaos uploaded a customized version of the modding framework Harmony that was simply called “Harmony (Redesigned).” According to the report, Chaos also “redesigned” a few existing mods that listed his version of the framework as the main prerequisite, essentially forcing players to install it instead of the original. Harmony is an essential component to many mods, and without it, players will not be able to use certain custom content.

Later, it was found that the redesigned Harmony came with an automatic updater that could allegedly install malicious software like keyloggers, Bitcoin miners and many others. Because of this, Chaos was banned from Steam, and his attempts to return to the platform were prevented.

Cities Skylines lets players create the cities of their dreams with realistic simulations and management mechanics Colossal Order

“Harmony (Redesigned),” the “Network Extensions 3” and the “Update from Github” mods were also banned from the Steam Workshop, according to the “Cities: Skylines” team. In a recent post, the developers clarified a few issues regarding the fiasco caused by the malicious modder.

First, the team said that none of the mods in the Steam Workshop have any key logger, Bitcoin-mining software, viruses, or any similar object. However, they mentioned that the “Update from Github” mod was removed because it could change Workshop subscriptions without the user’s permission, which could potentially lead to abuse and the installation of malware onto a user’s PC.

Next, “Network Extensions 3” was removed over a violation of the Steam Subscriber Agreement. The team mentioned that the mod “discriminated against specific Steam users” as it prevented certain modders and employees of Colossal Order (the developers) from accessing the game.

Lastly, the developers found that “Harmony (Redesigned)” has not been updated since 2021, but it was still removed because its mod author was banned.