I took contract in which I had to find the money inside an account. I had proxy bypass and monitor bypass. I sent the value and I transferred all the money into my account. I deleted transaction logs of account and connection logs at one of the nodes. But I was still caught, is it a bug or did I miss something?

Ah everything is gone due to a single mistake. :(
The guide you linked to is really good. Thanks, firedash.

One good steal of 500k will raise your ranking to Uber-skilled.

The ranking may be based more on how much money you have since that tells what programs/equipment you have more so than what you can do.