I want to highlight that almost every topics regarding this achievement does not ever mention getting the achievement
on Steam. There has only ever been one person called "Phoenix Red" who claims to have it unlocked on Steam with the VPN method.
I'm not sure if the discord mentioned above is the same as this one
https://discord.gg/8en7xSJ as the link is dead. I've been digging around in this one and see only 3 people mentioned to have the achievement. Of the three people mentioned, one of them was actually on the PS4, not Steam.
Another one is "Phoenix Red", who has been really busy posting the VPN "method" on Steam Discussion forums and all over Discord. I actually contacted this person all the way back in 2021 and all this person had to say was that they used a VPN from Asia. They did not mention anything about deleting or editing files. I've found out that since then, this person's explanation of how they got the achievement had only gotten more elaborate as shown in the discord mentioned.
I don't know if this person is on TSA but their astats account exists and it shows that every of their Infinite Warfare achievements is invalid.
https://astats.astats.nl/astats/User_Achievements.php?Type=8...