There is a potential security issue that has affected the “Traffic” mod for Cities: Skylines II. Late Monday evening, an outside actor pushed an update to the mod, which includes a .dll file which we believe is malicious. We have already removed it and the current version as of 2024-10-31 15:35 CET is safe to download and use, but if your mod synced and you played the game using the mod between Monday and then, there is a possibility that you may have the malicious file.

We are working to determine the nature of this .dll, and we will update you as soon as possible. In the meantime, please take the following steps as soon as possible to secure your system:

• If you have not played with the Traffic mod and have not subscribed nor downloaded it, there should be no risk to your system and nothing you need to do.
• If you have the Traffic mod and have not played Cities: Skylines 2 between Monday and today, let the mod sync as normal, and the malicious file should be deleted automatically. Please still scan your system with an anti-malware program like Windows Defender.
• If you have played using the affected version, please check your local files. If you have any malicious files installed, you will find them here; %localappdata%low\Colossal Order\Cities Skylines II\.cache\Mods\mods_subscribed\ inside the folder 80095_13
• Note that it is only specifically the 80095_13 folder that will contain malicious files; if you do not see this folder, you do not have the compromised version of the mod.
• If you do locate this folder, use an antivirus or antimalware program to quarantine it and/or remove it from your system, and run a thorough scan of your drives.
• As a precaution, we recommend changing your passwords.

We are working on the following steps to ensure you can enjoy our mods safely and securely:

• We will be going through all files uploaded to Paradox Mods and see if any other mods have had unexpected updates.
• We have contacted the modder whose mod was compromised and discussed our recommended steps to secure their account. They have updated Traffic to a safe version, so anyone playing with version v.0.2.4 is playing with a safe version.
• Paradox Mods will receive an update that notifies modders when their mods have been updated so that creators are quickly alerted to changes they have not personally made.

Sharing creative game content is at the heart of our community at Paradox, and we will continue to ensure you can explore mods safely.

As an important reminder, do not share your account information or passwords with anyone; we will never directly ask for your password or personal information.