Recently we noticed spammers abusing Dropbox, a popular cloud-based, file-hosting and synchronization tool, to spread spam.
Dropbox accounts have a public folder where files can be placed and made publicly available. This function is useful to spammers, as it effectively turns Dropbox into a free hosting site. Spammers have abused URL shortening and free hosting sites for some time. Dropbox also provides a URL shortening service, which spammers have also abused.
Spammers have created several Dropbox accounts, uploading an image and a simple .html file and then using the image to link to a pharmaceutical site.
Following this link takes you to a fairly standard "Canadian Health & Care Mall" site:
We saw over 1,200 unique Dropbox URLs being used in spam...