Spammers attaching .ZIP files with HTML inside

Since about 1am GMT today, I've seen a steady stream of messages with .ZIP attachments hit my spamtraps. The Zip files seem to contain a simple HTML page spamvertising the usual fake ED drugs.

Subjects include:

• On Top All Night
• Your Sexual Health
• Master in bed are you
• Smart in bed games
• Be a big bed man

There seem to be two templates in use:

1. a simple plain text body and a .ZIP attachment
2. an HTML body (plus /alternative plain text) with the .ZIP file as a /related part