Facebook has fixed the problem and says spammers are using friend lists they scraped before the fix to send new e-mails.
Are you getting spam that has a Facebook friend's name listed as sender but was actually sent from an unknown e-mail address? Me too.
These are vestiges of an attack that exploited a misconfiguration on Facebook that was fixed last week, according to Facebook. Though spammers aren't scraping any new friend information off Facebook accounts, they are apparently using previously obtained data to send spam. That means the messages could come until e-mail providers are able to find the source of the spam and shut the spammers down.