Capcom pushed out an update for Street Fighter 5 on September 22 as promised. While most PC users happily installed the new update, little did they know about the trouble packed inside it. Capcom’s update not only broke the game for many but also posed a security risk, reported Polygon. That drove fans mad for they were unable to launch the game, frame rates were inconsistent, faced issues with anti-virus, and even received Windows warnings.

The latest SFV update is out now! New stage interactions, daily challenges, colour packs, VS CPU mode and the Vice President himself, Urien. pic.twitter.com/jhYKoL8MPX – Capcom UK (@Capcom_UK) September 23, 2016

While the Street Fighter 5 players were waiting for the promised September content update, Capcom quietly released a “client-side security update” via Steam for the PC users. This update installed a file called “capcom.sys” as an anti-crack solution (note: not DRM) to prevent cheating and illegitimately acquiring in-game currency. Also, the players would have to click confirm every time they start the game to authenticate the game driver, even in the offline mode.

Many players complained about the same to the Street Fighter‘s social accounts and other online avenues. Capcom realized the gravity of the situation and quickly apologized with a confirmation to investigate the issues with the PC version of the Street Fighter 5.

The official Capcom blog post suggested a few workarounds for Street Fighter 5 players like adding a file to exceptions list of anti-virus or disabling security software temporarily.

@StreetFighter See these pictures? NO. NO NO NO. DO NOT PUNISH US JUST FOR PLAYING ON PC. REMOVE THAT “DRIVER” ASAP. pic.twitter.com/LgtgnRisk1 — Will (@wmarone) September 23, 2016

“The new anti-crack/anti-cheat solution prevents memory access certain ways, so perhaps this is creating a false-positive situation that may trigger either the anti-virus software or Windows DEP,” the post read.

But that didn’t help to get the game started. A Reddit user was left aghast when the game threw a fatal error and wouldn’t launch even in Admin mode.

Another Reddit user, who goes by the name LoGicMoTion, posted that the new security update for Street Fighter 5 installed a file that accessed kernel-level information of the Windows installation. Not only that, the game would ask for Admin access every time it is launched.

Ideally, game files have no business sneaking around the Windows kernel area and not ask for Admin access, unless the User Access Control acts up.

A Twitter user named Bill307_a investigated the nature of the “capcom.sys” file and discovered that it had a piece of code meant for making “rootkits” to compromise PCs.

On Street Fighter 5‘s official page on Steam, Capcom posted about the rollback patch that removes the previously installed anti-crack code. But to everyone’s surprise, it turned out to be a half-baked solution. The rollback patch did not delete the “capcom.sys” file from the PC.

The rollback to the PC version of SFV prior to the security measure update is now live. The new September content is included. — Street Fighter (@StreetFighter) September 24, 2016

The NeoGAF forum users were surprised at first to learn that Capcom’s Street Fighter 5 update installed a rootkit, and were mad for the rollback patch failed to remove it from the PC. A few users suggested manually removing the “capcom.sys” from the “System32” folder of the Windows and reboot the PC.

On the other hand, the latest patch also broke the PlayStation 4 version of the game by corrupting the installation files and making it unplayable.

While Street Fighter is Capcom’s important title, the company’s intention of adding anti-cheat solution seems legitimate at face value. However, programming the solution to install a rootkit or open a backdoor and putting thousands of PCs at risk is certainly questionable.

Capcom’s rollback patch for the Street Fighter 5 update is not the solution everyone wanted. It just pushes the company further in the troubled waters. As it is, the lackluster launch of the game affected the sales of Street Fighter 5, reported the Inquisitr. And this “rootkit” masked as an anti-cheat code solution only adds fuel to the fire.

[Feature Image by Capcom]