I also haven't heard this term before. But i did quick search and found out term "for profit attack" was mentioned on first edition of Mastering Bitcoin. Specifically it's located at chapter 8, page 217.
The massive increase of total hashing power has arguably made bitcoin impervious to attacks by a single miner. There is no possible way for a solo miner to control even 1% of the total mining power. However, the centralization of control caused by mining pools has introduced the risk of for-profit attack by a mining pool operator. The pool operator in a managed pool controls the construction of candidate blocks and also controls which transactions are included. This gives the pool operator the power to exclude transactions or introduce double-spend transactions. If such abuse of power is done in a limited and subtle way, a pool operator could conceivably profit from a consensus attack without being noticed
Since Bitcoin consensus doesn't force miner to include all or certain transaction, there's nothing Bitcoin community could do aside from asking miner switch to pool which doesn't perform such attack.
Yeah, I've read through this, but didn't know how to share a clickable link that'll lead to the exact place where I saw the term, however, regarding the double spending, a mining pool (not saying their operators are into such practice) control about 28-31% of the total mining hashrate according to
mempool stats, and I just figured that it doesn't really have to be 51% of the hashrate to perform a double spend, that 30% can also execute such an attack. Hence, if that's possible I think I'm clear about the double spending capability of for-profit attack. As you can see the term wasn't explained in details, that's why I asked here to know more about it, the techniques and what can be done about it. Your answer is good, moving people away from a suspected mining pool controlled by tricky operators can help reduce such threat by diminishing the hashrate of the pool, yet it's written that if it's been done carefully they'll go unnoticed. So, I'm wondering if no method exist that can bench or stop for-profit attackers even though a mining pool does that secretly. Or its centralized nature keeps the for-profit attack operators immune from sanction or restriction?