This is how to check if people you played with in CSGO have VAC bans
Almost every player has run into a cheater in Counter-Strike: Global Offensive, whether they know it or not. The problem is so widespread that Valve’s anti-cheat routinely bans thousands of players each day.
With cheats for CSGO so widespread, there’s an easy way to check your own match history players that have bans on their account, and you don’t have to upload match codes to do it.
Checking your match history for VAC-banned players
A plugin called Ban Checker for Steam is available for both Google Chrome and Mozilla Firefox and allows you to check your match history for players banned by Valve’s anti-cheat. After downloading the extension, log in to Steam through your web browser.
Click on your profile name and then “Games” from the list on the right-hand side. Find Counter-Strike: Global Offensive and select “Personal Game Data.” This option will take you to a page where Valve has stored all of your stats from CSGO, including your profile’s whole match history.
Go here to generate your personal Steam API key by using the account name that you log in to Steam with for the domain name and copy it. This allows you to pull game data from the Steam API.
Click on “Competitive Matches” and then “Set Steam API key” above your matches. Select “Use Custom API Key” and paste your API Key and save. Reload the Personal Game Data page, click “Load whole match history.” Pulling the matches from the Steam API can take a while, but once it’s finished click “Check loaded matches for bans.”
On this account, we found that around 3% of players that we played with had been VAC banned. That’s much less than most stories would suggest. Either way, now there’s a way to check for banned players in your past games. Now you won’t have to wonder whether that last suspicious opponent was just having a particularly lucky day.