Is it possible to detect someone trading?

[송승환]

Recently I got scammed on trading website. They say I got API scammed because the bot I traded with was not their official trading bot.

That means the 3rd party bot somehow was tracking my profile or the official trading bot.
However I can't understand how this is technically possible. Even though the scam bot had my/official bot's steam trade api link, the API can only access accepted/cancelled trades, not ongoing ones. When I requested trading on the website, the scam bot immediately offered trading. how is this possible?

[♛⁧Schultheiß]

It means your API key is compromised.
If you didn't input your API key anywhere, it means your PC is compromised.

[송승환]

+ I only play cs2 in internet cafes and regenerated my api key before trade. plus even though my api key is compromised, I want to know how can someone detect the "ongoing" trade which cannot be viewed yet on my trade history.