The little fox wallet was stolen! Can someone analyze what the reason is?

Because I saw a blockchain game that I wanted to play, I logged into an old little fox wallet and found that the funds inside had already been transferred out, although it wasn't much.

But I'm very curious about how it was stolen, as I rarely used it and didn't participate in any scams.

Later, I thought back and realized that I often use a VPN, which might be one reason, and another reason is: I am used to using the Tampermonkey plugin in my browser, and the browser also has developer mode enabled, so this might be a more significant reason?

By the way, I also stored a copy of the keywords on WPS Cloud and Tencent Weiyun. Could this be a reason?

I checked the blockchain records and found that the outgoing account address is a habitual offender, with 429 transfer records, the outgoing were all transaction fees, while the incoming ranged from 1 ETH to 0.000 something ETH; he doesn't miss anything that is more than the transaction fee 🙂‍↕️🙂‍↕️🙂‍↕️