Freeware is proprietary software that can be used free of charge. A popular vector for distributing freeware is download portals, i.e. websites that index, categorise, and host programs. Download portals can be abused to distribute potentially unwanted programs (PUP) and malware. The abuse can be due to PUP and malware authors uploading their ware, by benign freeware authors joining as affiliate publishers of pay-per-install (PPI) services and other affiliate programs, or by malicious download portal owners. The authors perform a systematic study of abuse in download portals. They build a platform to crawl download portals and apply it to download 191 K Windows freeware installers from 20 download portals. They analyse the collected installers and execute them in a sandbox to monitor their installation. They measure an overall ratio of PUP and malware between 8% (conservative estimate) and 26% (lax estimate). In 18 of the 20 download portals examined the amount of PUP and malware is below 9%. However, they also find two download portals exclusively used to distribute PPI downloaders. Finally, they detail different abusive behaviours that authors of undesirable programs use to distribute their programs through download portals.