VAC bans received on multiple accounts that only idled CS2 using ASF

[Mascot2Steam]

Hello,

I'm writing because I received VAC bans on several Steam accounts that were idling Counter-Strike 2 using ASF. In some cases, these were main accounts where I legitimately played CS2 without ever using any cheats or third-party tools. Other accounts were created only to idle time with ASF.

Here’s a full breakdown:

• I used GamesPlayedWhileIdle = CS2 appid in my ASF config.
• No cheats, injectors, or modifications were ever used on any account.
• Some accounts had real gameplay in CS2, others only idled via ASF.
• In every case, the VAC ban appeared shortly after idling CS2.
• None of the accounts had the CS2 client launched manually at the time of idling.
• No third-party tools were active during idling — only Steam + ASF.

I understand ASF interacts only with Steam's Web API and shouldn’t cause any VAC-related issues. However, this situation is extremely confusing and concerning, especially since it affected clean, active accounts as well.

My questions:

1. Could CS2’s specific VAC behavior somehow be triggered just by idling the game using ASF?
2. Have you heard of similar cases lately from other users?
3. Would you recommend avoiding CS2 in GamesPlayedWhileIdle for now?

I’m not suggesting ASF is at fault — it’s a fantastic tool that I’ve trusted for years. But these bans seem to have been triggered only after CS2 was idled via ASF, and I’d appreciate any technical insight or recommendations you can share.

Thank you for your time and your work on this project.

Best regards,
Max

[Rudokhvist]

Just for your information, take those factors into consideration:

1. Accounts can be banned "by chain", if they are using same phone number (or maybe even was used from the same client, not 100% sure about that part). So, it may be just one VAC ban, propagated to "clean" accounts connected to the banned one.
2. You say that accounts where banned shortly after idling CS2 - what time is "shortly"? Usually VAC bans are delayed, and account is banned in about week or so after violation (not sure about exact delay). If it was just a few hours or even couple of days - it may be not connected with idling CS2 in ASF.
3. VAC may be triggered not only by actual cheats, but also by some other software, such as debuggers, sandboxes, keyloggers, etc. If someone actually played CS2 some time ago (see 2), and had some intrusive software in the background (with no intention of cheating) - it may still have triggered VAC on that account, and than that account propagated to the rest of accounts (see 1).

Good luck in your investigation!

[JustArchi]

Statistically speaking, if that was a global issue we'd have not even hundreds but thousands if not more reports from different people that it affected their accounts and they were using ASF.

You're the first one to report suspected VAC ban caused by ASF since years, that speaks on its own, but I don't like to base my judgment on statistics and theory, but rather facts, and the facts are following:

1. Having CS2 in GamesPlayedWhileIdle, using it in play command or farming cards from it does not do anything else than telling Steam we're playing given game.

2. For interacting with CS2 game, you need to send requests to GC server - game coordinator, which is something ASF doesn't do. There are plugins extending ASF with such functionality, such as CS2Interface. Using plugins like that can totally result in a VAC ban, as at this point you're actively interacting with the game in similar way how your Steam client does. Of course, this is far less likely than real game, as there is no process-level detection going on, but in some extreme case I could believe that Steam would VAC-ban user based on GC communication alone - I've never observed this, and I'm far from believing that ever happened to anyone, but it is a possibility in some extreme cases.

3. From practical perspective, if you launch a game through ASF, and GC communication does not happen, Steam can't know whether that's due to network issues, game crashing, process not launching, game booting slowly or anything else. They can't give you VAC ban for that, as it'd be equal to handing out VAC ban when somebody starts the game from Steam and immediately losses network connection, failing to communicate with the GC. Not to mention that you can still play the game offline (even with Steam online), in which case no communication is done at all.

Taking above into account, using my best judgment, I don't believe what you've explained above is possible. Maybe if you've confirmed that you've never launched CS2 at all on any of your accounts and they still somehow got banned, I could believe in point #2 above or something similar. But as it stands right now, far more likely scenario is that you've been running something on your computer that caused full VAC system in the CS2 game (that you've also been running) to detect it, and hand out VAC ban in the result. The fact that other accounts got VAC ban too even without ever launching the game is not any clue or proof, it's normal that Steam hands VAC bans in chain-like matter, it's enough for those accounts to share same phone number as your main one to get a VAC ban, even if they don't own the game at all (which is kinda funny).

And note that I'm not saying you've been actually using cheats or anything like that - a lot of virsues, malware and even legitimate software (such as kernel-level anticheats, funny) can cause behaviour like that. Even running kernel-level VMs, could in some extreme cases cause misdetection. There are far more possibilities here, and it's impossible to tell what caused it for sure.

You've asked for technical insight so I did my best to dig into internals and analyze this as you've requested. It's always possible that I'm wrong, but it's extremely unlikely if you take into account both technical arguments, as well as statistical ones, where we don't observe people with CS2 launched in ASF getting VAC banned globally, and out of 4.5 million Steam accounts I'm sure we'd have at the very least solid 0.1%, so 4500 accounts banned like that, probably at least 5% of accounts play CS2 in ASF if not more. Of course, you can always find people that will claim ASF caused them VAC ban, same as I wrote in the FAQ, but if ASF really caused that, we'd have thousands of such reports, not a few users out of half a million affected by this.

[JustArchi]

ASF does not attempt in any way to hide your ownership of the accounts, Valve could totally link all those accounts together based on ASF traffic alone. And that's intentional, because for people that do not attempt to abuse Steam, it's actually beneficial and decreases chance of accidental unjustified bans.

[Mascot2Steam]

Do you have any recommendations on how I could better isolate my other accounts to avoid potential bans in the future?

[JustArchi]

No, because one of the last things that I care about in ASF is to make it easier for people with abuse potential in mind to protect their asses. I care only about justified use cases of ASF, and ASF's transparency in this regard is beneficial to all users with clear intentions.

[Mascot2Steam]

I only have half a million steam accounts, what kind of abuse are we talking about?

[MikeLund]

I only have half a million steam accounts, what kind of abuse are we talking about?

Having half a million Steam accounts.