According to PC Gamer, after the end of Steam Summer Sale 40,000 user has been ban due to Valve Anti-Cheat. It all started in July 2017 making the biggest ban in history of Steam. There no great trick for a banned Steam user. You will lose all of your games and you have to re-purchase them. If you are playing CSGO and Team Fortress 2 you’re skins will be loss as well. As for myself I have don’t been banned but I encounter the problem when I played Team Fortress 2. Usually, a third-party programs are interfere with the program such as CCleaner, Powershell, Steam Idlers and more. You can find the issue here and follow the direction to resolve the problem.
If you don’t know what VAC stands for I will tell you. VAC is Valve Anti-Cheat is a program that defects cheat installed into your computer. Such as third-party modification to give a player an advantage over another. If the user decide to hack or input cheats into the game it will trigger a ban. This programs are safe from being ban such as X-Fire chat programs, system hardware configuration on your computer. VAC doesn’t affect all game but Valve only such as Team Fortress 2, Counter Strike, Half-Life 2: Deathmatch and more. If you want to learn more about the ban, here is the info. To report a cheater make sure you contact firstname.lastname@example.org and follow the instruction lean more. Cheating is not good sportsmanship, if you want to be the best. You have to work and become a better player. I hope this doesn’t have to anyone and be careful don’t get banned on Steam.