Scam ICO's are not an incorporated company.
The people behind the "project" are unknown/fraudulent team members/advisors.
They promise high/fixed profits if you invested.
Plagiarized/bad whitepaper.
Token distribution structure doesnt make sense (e.g. 35% for founders)
Team dodging questions by the community (Refusal to disclose company info)
You can read in details from the source here:
https://blog.indorse.io/how-to-spot-a-scam-ico-d2cfe47b3b52