Is leaking lectures and signing attendance for absent students considered a sin, and what is the correct action in such cases?

The outcome of patience and diligence is goodness and success, and Allah does not let the work of those who do good go to waste. Recording lectures and publishing them so that those who did not attend can benefit is permissible, as long as the professors do not prohibit it. However, for some students to sign on behalf of their absent colleagues is not permissible, because it is a lie and deception. Whoever does this and is not deterred by advice, then the officials must be informed about them.