Valve Anti-Cheat: История и Эволюция

Anti cheat software

Valve Anti Cheat (VAC) is an anti cheat tool developed by Valve as a component of the Steam platform, first released with Counter Strike in 2002. When the software detects a cheat on a player's system, it will ban them in the future, possibly days or weeks after the original detection.

In 2001, Even Balance Inc., the developers of the anti cheat software PunkBuster designed for Counter Strike and Half Life mods, stopped supporting the games as they had no support from Valve. Valve had also rejected business offers of integrating the technology directly into their games. Valve started working on a "long term solution" for cheating in 2001. VAC's initial release was with Counter Strike in 2002. During this initial release, the system only banned players for 24 hours. The duration of the ban was increased over time; players were banned for 1 year and 5 years, until VAC2 was released in 2005, when any new bans became permanent. VAC2 was announced in February 2005 and began beta testing the following month. On November 17, 2006, they announced that "new [VAC] technology" had caught "over 10,000" cheating attempts in the preceding week alone. During the early testing phase in 2002, some information was revealed about the program via the Half Life Dedicated Server mailing lists. It can detect versions of "OGC's OpenGl Hack", can detect OpenGL cheats, and also detects CD key changers as cheats. Information on detected cheaters is sent to the ban list server on IP address 205.158.143.67 on port 27013, which was later changed to 27011. There is also a "master ban list" server. RAM/hardware errors detected by VAC may kick the player from the server, but not ban them. Eric Smith and Nick Shaffner were the original contacts for game administrators. In February 2010, the VAC Team consisted of Steam's lead engineer John Cook and his team of 16 engineers. In July 2010, several players who successfully used information leaked from Valve to increase their chances of finding a rare Team Fortress 2 weapon called the Golden Wrench were banned by VAC. During the same month, approximately 12,000 owners of Call of Duty: Modern Warfare 2 were banned when Steam updated a DLL file on disk after it had been loaded into memory by the game, causing a false positive detection. These bans were revoked and those affected received a free copy of Left 4 Dead 2 or an extra copy to send as a gift. In February 2014, rumors spread that the system was monitoring websites users had visited by accessing their DNS cache. Gabe Newell responded via Reddit, clarifying that the purpose of the check was to act as a secondary counter measure to detect kernel level cheats, and that it affected fewer than 0.1% of clients checked which resulted in 570 bans. As of May 2016, the system began banning accounts that were registered with the same phone number. Additionally, a phone number that was used on an account at the time it was banned will not be allowed to be re registered on other accounts for three months. The system has been criticized for failing to detect LMAOBOX, a popular cheat program for Team Fortress 2, until May 2016, which resulted in a wave of bans. In February 2017, Valve announced plans to introduce a machine learning approach to detecting cheats in Counter Strike: Global Offensive, and that an initial version of the system was already in place, which would automatically mark players for manual detection by players through the "Overwatch" system. In March 2018, Valve publicized said machine learning based approach in a talk at the Games Developer Conference, naming it VACNet. In October 2023, certain users of AMD graphics cards were banned from Counter Strike 2 after AMD added support for their "Anti Lag+" feature via a driver update, which the game flagged as a cheat due to it detouring certain DLL functions. AMD subsequently withdrew the driver update and Valve pledged to unban any affected users.

Valve rarely discusses the software, as it may help cheaters write new code or conduct social engineering. According to Steam's lead engineer John Cook, to stop the anti cheat software itself from being exploited, "The software is constantly updated and sent down in small portions for the servers as needed, so hackers only get to see small portions of it running at any particular time. So while they may be able to work around pieces of it, they can never hack everything." that the account is permanently banned from "VAC Secure" servers for that game, possibly along with other games that use the same engine (e. g. Valve's Source games, GoldSrc games, Unreal Engine games). Valve never discloses which cheat was detected. Players have criticized the system for taking weeks to months to ban cheaters. Large numbers of flagged accounts may also be banned in "waves" or “VAC waves”.

The user's Steam profile is also marked with "ban(s) on record", which is publicly visible and cannot be hidden, regardless of the profile visibility of the banned account. An analysis of 43,465 users that had been banned between April 2011 and October 2011 showed that the more VAC banned players a user is friends with, the more likely they will also be VAC banned themselves in the future. After they were banned, they lost more friends, were more likely to increase their privacy settings and also had more VAC banned friends than non banned players. Banned players are also sometimes referred to as going on "VACation". he initially denied using a cheat, claiming it was caused by "a friend of his played on one of his smurfing accounts which mail is linked to his main account". Then in 2015, he admitted to using a cheat. Hovik "KQLY" Tovmassian, Simon "smn" Beck and Gordon "SF" Giry were banned shortly before they were scheduled to play at DreamHack Winter 2014. The ESEA League claimed the bans were a result of working with Valve directly. Simon "smn" Beck and Hovik "KQLY" Tovmassian both admitted to using cheats. In March 2020, Elias "Jamppi" Olkkonen filed a lawsuit against Valve, alleging that a lifetime VAC ban negatively affected his esports career, specifically his inability to play in Valve sanctioned Major tournaments, which subsequently prevented him from signing onto the esports team OG. the lawsuit alleges that a lifelong VAC ban for a minor, particularly without the ability to first plead his case, is unreasonable. A few users used to collect VAC bans, but this was eventually made less prolific as Valve updated the VAC ban message shown on the user's profile, now showing "Multiple VAC bans on record" instead of the actual number of VAC bans.