I'm pretty sure I've played VAC secured games with Wireshark open in the background many times without issue. In my experience VAC is pretty lenient on what you do outside of the game to begin with.
I did get shadowbanned from Modern Warfare (2019) for two weeks though. At first I couldn't figure out why my game suddenly would keep crashing on the main menu every time I started it. After a reboot of my PC it stopped crashing, but now the game was taking forever to find a match and when it finally did I got put in a lobby with high ping players from across the world, half of which were obviously cheating.
I managed to figure out that I had HxD (a hex editor) open in the background before I rebooted because I was messing around with the save files of another game. Simply having a process running called "hxd.exe" will cause the game to "crash" and shadowban you for a while. I verified this by renaming notepad to hxd.exe and observing the same thing.
I did get shadowbanned from Modern Warfare (2019) for two weeks though. At first I couldn't figure out why my game suddenly would keep crashing on the main menu every time I started it. After a reboot of my PC it stopped crashing, but now the game was taking forever to find a match and when it finally did I got put in a lobby with high ping players from across the world, half of which were obviously cheating.
I managed to figure out that I had HxD (a hex editor) open in the background before I rebooted because I was messing around with the save files of another game. Simply having a process running called "hxd.exe" will cause the game to "crash" and shadowban you for a while. I verified this by renaming notepad to hxd.exe and observing the same thing.