Well-known companies such as Dell Inc., Yahoo Inc. and Marriott International Inc. are lobbying Congress for tougher laws targeting online scammers who profit from their brand names.

United as the Coalition Against Domain Name Abuse, 10 companies have hired the law firm Alston and Bird to persuade federal lawmakers of the need to crack down against those who claim Web addresses, or domain names, that include — or even resemble — a legitimate company’s trademark.