Valve Anti-Cheat

Valve Anti-Cheat Icon

Valve Anti-Cheat, otherwise known as VAC, is an anti-cheating system released by Valve in 2002. It was used mainly for multiplayer Steam games, including all main titles of the Counter-Strike series.

When a player is detected cheating in a VAC-Secure server, the player will be marked for cheating and will get banned from VAC servers permanently. VAC bans are non-negotiable and cannot be removed.

To obtain drops in Global Offensive, it is required to play in a VAC enabled server. Drops are unavailable in servers that are not secured with VAC.

History

This window appeared when attempting to connect a VAC-Secured after being banned

With the first version of VAC, a ban took force almost instantly after being detected, and the cheater had to wait 2 years to have the account unbanned. Since VAC's second version, cheaters are not banned automatically. With the second version, Valve instituted a policy of 'delayed bans', the theory being that once a new hack is developed which circumvents the VAC system, it will spread amongst the 'cheating' community - by delaying the initial ban by approximately 3-4 weeks, Valve hopes to identify (and ban) as many cheaters as possible.

Some servers implement a 'vote-kick' or 'vote-ban' system that allows players to vote to kick or ban alleged hackers from a single server. To some players, this human-based system is much more effective than the VAC system. The idea of a human-run cheat identification system was implemented as the Overwatch system.

Since 2017, Valve has been implementing deep learning systems (known as VACnet) to detect cheaters with more certainty and deliver them to the Overwatch system.

Drawbacks

Like any software detection system, some cheats are not detected by VAC, and at times the only effective anti-cheat solution is a human administrator watching an online game. Some servers implement a vote system, in which case players can call for a vote to kick or ban the cheater.

VAC's success at identifying cheats and banning those who use them has also provided a boost in the purchasing of private cheats. These cheats are updated frequently to minimize the risk of detection, and are generally only available to a trusted list of recipients who collectively promise not to reveal the workaround.

Overwatch

Main article: Overwatch

Overwatch is a player-driven cheat jurisdiction process featured in Counter-Strike: Global Offensive, which works in tandem with VAC.

Cheating

The new notification received after being VAC banned in Global Offensive

The VAC ban main menu banner message as seen in Counter-Strike: Global Offensive after a cheating infraction.

Example of ESP Cheating, showing player's location through wall, health bar and extra information

The Counter-Strike series has been a prime target for exploitation by cheaters since its release. In the player community, cheating is often referred to as "hacking" in reference to programs or "hacks" executed by users.

Common Hacks

These hacks are usually either standalone or come bundled together as part of a multihack.

Wallhack

A wallhack cheat allows the player to see through walls. These function by displaying objects that are normally obscured or replacing opaque game textures with semitransparent ones, allowing the hacker to see enemies before they would normally be in view. As the engine only renders the immediate area around the player, this does not allow a player to see the entire map at once.

Speedhack

Speedhacks give the player increased speed, usually dramatically increased speed making it hard to target, hit, or even see the player. It works by sending false synchronization data to servers. Because that it increases the cheater's speed, it's easily recognized by other players.

Spinhack

Also known as a Spinbot, a player using a spinhack appears to spin rapidly in all directions, reducing the player's overall hit area and confusing the enemy. From the perspective of a player using a spinhack, the game looks and controls normally. Due to the obvious nature of this hack, it is most commonly used by players who aren't attempting to hide the fact that they are cheating.

Anti Aim

Anti Aim is a cheat that flips, tilts, or otherwise rotates a player's hitboxes so that their character model does not align with them, making it much harder to reliably hit them. Anti Aim may also refer to cheats that misrepresent the location of a player's hitboxes. This does not change the actual location of the player's hitboxes, but instead causes more basic aimbot or silent aim hacks to miss.

No recoil

By reducing or removing the recoil entirely, recoil cheats keeps the player's gun shooting straight on the y axis without a kickback by removing gun physics.

No spread

Similar to a no recoil cheat, the no spread cheat makes the player's gun shoot straight along the x axis. Combining this with a no recoil cheat and an AK-47, makes a pretty scary enemy to play against.

Aimbot

Either through the use of scripting or prediction, aimbots helps, or takes over the players aim, by moving the player's view to anticipate an enemy's position. They are usually programmed to aim specifically for the head. Most aimbots are programmed to ignore recoil and spread.

Auto Firing/Triggerbot

Usually used in conjunction with an aimbot, auto firing automatically fires at enemies in the player's crosshairs. Using this as a standalone cheat, makes it one of the less recognizable cheats, from other players's perspective. Triggerbots can often be set to ignore players behind walls, to hide the cheat.

Silent Aim

Similar to the aimbot and auto firing hacks, the silent aim hack allows a player to shoot at an enemy without having to actually aim at the enemy. From all points of view (player, world, or spectator), the player is not seen aiming at the enemy when the kill takes place.

Radar Hack

Radar hacks work similarly to wallhacks, in that they reveal the location of enemies where a cheater would not normally know that information. However, radar hacks achieve this by permanently displaying the location of enemies on the radar, rather than allowing a cheater to see them through walls. Radar hacks are less powerful than wallhacks, but are also far harder for a human observer to detect specifically because of this lower power.

Barrel hack

The barrel hack shows a line that depicts where the enemy is looking.

Anti-flash and anti-smoke (also known as removals)

Removal cheats disable or hide the flashbang and smoke grenade effect. This is branched off the aforementioned wallhack.

Bypassing

Although certain console commands can be activated for an entire server, bypassing allows the player to activate console commands normally restricted by sv_pure or sv_cheats.

ESP (Extrasensory Perception)

An ESP cheat shows textual information about the enemy, such as, health, name, and distance, and also information about weapons lying around the map, which could be missed without the hack. However, some legit server mods may actually make such information available to the player. The cheating occurs when the information is obtained where it would otherwise be hidden from the player.

Other Hacks

Upside-Down Hack

This hack allows a player to flip the player's view upside down. It is often utilized to allow normal shots to the leg to be directed to the head of a target. However, the hack is very frustrating to use and is completely counterproductive due to the amount of difficulty it puts on aiming. Thus, the hack is often enabled along with an aimbot.

Humanization

Humanization is a modification of aimbot hacks that gradually pull the cheater's aim closer to their intended targets rather than instantly snapping onto them. This makes it far harder for human observers to detect that the cheater is using an aimbot.

Fakelag

A fakelag hack exploits the way CS:GO servers handle latency by sending fake information about the cheater's ping. This tricks the server into thinking the cheater is experiencing far more network latency than they actually are. This can allow cheaters to perform peeks and kill enemies before they are even visible to the enemy, without actually suffering any negative effects from lag. This hack can be very difficult to spot as it looks similar to CS:GO's intended lag compensation.

Backtrack

A backtrack hack exploits CS:GO's built-in lag compensation by sending fake latency information to the server in order to hit targets that are no longer visible, effectively allowing cheaters to pull targets back to where they were moments ago. Because lag compensation has a maximum cap, this hack can only backtrack targets a few hundred milliseconds, but even this can be a significant advantage especially when paired with other hacks. This hack can be very difficult to spot as it looks similar to CS:GO's intended lag compensation.

VAC Module Disabling

This cheat must be loaded before the Steam client is even launched, and prevents VAC from loading at all. By faking signatures that would normally be sent by VAC, VAC-secured servers can be tricked into thinking VAC is running on the user's computer when it in fact is not. VAC cannot detect anything from a player who has successfully disabled VAC from loading, though cheaters may still receive Overwatch or Untrusted bans.

Auto Strafe

This hack automatically performs "air strafes" for the player while in midair, which will increase the player's speed before they land. This hack will perform a set of inputs that will increase a player's speed to the maximum possible through air strafing. This typically looks like a player's first-person view rapidly vibrating while in midair.

Auto Bunnyhop

This hack automatically jumps for the player while toggled, guaranteeing a successful bunnyhop every time (without modification, even perfectly timed jump commands will only result in a successful bunnyhop half of the time on average). This is distinct from using the scroll wheel to input several jump commands in a short time window (which is not considered cheating,) which only makes the input timing easier and does not guarantee a successful bunnyhop.

Teleport Hack

A cheater with this hack can choose where to (re)spawn in a map. It can be near enemies, hard to reach spots, or even outside the map boundaries. A player with aimbot and wallhack can eliminate targets without being easily spotted or shot at.

Non-VAC triggers

Some behavior exhibited during a game borders on cheating, is generally unfair, or can disrupt the game for the others playing, but is not considered cheating by VAC standards. Such behavior is independently policed by the server's administrators and will vary from server to server.

Ghosting

Many players consider Ghosting a form of cheating. Ghosting is when a dead player who is spectating informs the player's live teammates of the enemies' movements, usually outside of the in-game voice chat. In a technical sense, ghosting is not a form of cheating as it does not modify any game files. Ghosting is not as prevalent in competitive mode, as dead players can only glimpse enemy movements for a few short seconds before being locked to spectating only other teammates, providing only minor information. Classic Casual does not allow dead players to chat (both voice chat and text chat) with alive players to prevent Ghosting. Users connected and spectating a match via GOTV are subject to a timed delay to disallow ghosting.

HUD Modifiers

HUD Modifiers change or remove certain elements of the Heads-Up Display. Typically, HUD Modifiers are used to remove elements of the HUD that are intended to limit a player's vision, such as the blacked-out portions of the screen when zooming in with an AWP. This allows players to view a much wider area than they otherwise would be able to, eliminating one of the downsides of remaining scoped-in for extended periods of time. Players must bypass the sv_pure convar to use this hack if sv_pure is set to "1" (as on all official servers.)

FOV Modifiers

An FOV modifier changes a player's field of view (FOV) beyond what is normally allowed by the game. Typically, FOV Modifiers are used to increase a player's field of view, allowing them to see and react to enemies that would normally not be visible on the screen without looking from side to side. They can also be used to prevent zoom-in effects from occurring when a player uses a scope, allowing them to retain their normal field of view without compromising accuracy. players must bypass the sv_pure convar to use this hack if sv_pure is set to "1" (as on all official servers.)

Disruptive behavior/Griefing

VAC will not ban players for disrupting online gameplay by team abusing, conflict with other players, spamming messages/voice chat, and other kinds of behavior that will annoy other players. VAC only bans players that uses the most recognized hacks. These actions are often countered with voting instead.

Client-side modifications

Although skin modifications are generally regarded as cosmetic changes that have no effect on game play, such mods can be used by the player to provide an unfair advantage. For example, replacing a firearm's third-person player model with one that is longer in length will allow the player to easily spot an enemy behind cover. In another instance, using player models with team-specific coloring permits the player to clearly distinguish between teammates and enemies.

Exceptions

A server with sv_cheats enabled

VAC does not ban players who use sv_cheats since it is considered to be a built-in cheat and it can only be enabled by an admin. If enabled, all players have the ability to use cheats. VAC will only ban players who use third party cheats.

Engines

VAC is not shared between GoldSrc and Source engines. For example, if a player is banned from GoldSrc servers, they can still play in Source servers.

Trivia

• Prior to the DreamHack 2014 tournament, Epsilon eSports and Titan were disqualified after members of each team were caught cheating by VAC.

External Links

• Valve Anti-Cheat on Wikipedia